Statistics Questions

Assume that X has a normal distribution and find the indicated probabil The mean is 15 2 and the standard deviation is 6 0 9 Find P 14 3 X 16 1 O 0 3413 O 0 8413 O 0 1587

If Z is a standard normal variable find the probability The probability that Z lies between 0 and 2 73 O 0 5032 O the answer is none of these choices O 0 9968

In airline applications failure of a component can result in catastrophe As a result many airline components utilize something called triple modular redundancy This means that a critical component has two backup components that may be utilized should the initial component fail Suppose a certain critical airline component has a probability of failure of 0 0056 and the system that utilizes the component is part of a triple modular redundancy a Assuming each component s failure success is independent of the others what is the probability all three components fail resulting in disaster for the flight b What is the probability at least one of the components does not fail a The probability is Round to eight decimal places as needed

The probability that a randomly selected 1 year old male feral cat will live to be 2 years old is 0 98037 a What is the probability that two randomly selected 1 year old male feral cats will live to be 2 years old b What is the probability that seven randomly selected 1 year old male feral cats will live to be 2 years old c What is the probability that at least one of seven randomly selected 1 year old male feral cats will not live to be 2 years old Would it be unusual if at least one of seven randomly selected 1 year old male feral cats did not live to be 2 years old a The probability that two randomly selected 1 year old male feral cats will live to be 2 years old is Round to five decimal places as needed

A random sample of 1953 adults was taken and they were asked if they prefer watching sports movies or news on tv They were also asked if they preferred dogs or cats Dog Cat Total Sports 371 148 519 Movies 524 138 662 News 480 292 772 Total 1375 578 1953 a What is the probability that a person selected at random likes dogs and movies b What is the probability that a person selected at random likes cats and news c What is the probability that a person selected at random likes dogs or movies d What is the probability that a person selected at random likes sports or cats

The answer above is NOT correct The shelf life of a batteries produced by one major company are normally distributed with a mean of 3 9 years and a standard deviation of 0 9 years The figure below shows the distribution of shelf lives of batteries produced by one major company Calculate the shaded area under the curve Express your answer in decimal form with at least two decimal place accuracy Answer 0004 3 297 4 8 Shelf Lives of Batteries Produced by One Major Company

College students average 8 2 hours of sleep per night with a standard deviation of 35 minutes If the amount of sleep is normally distributed what proportion of college students sleep for more than 9 3 hours Proportion 2 5 100

2 50 points eBook Karla Tanner opens a web consulting business called Linkworks and completes the following transactions in its first month of operations Prepare journal entries for each transaction and identify the financial statement impact of each entry The financial statements are automatically generated based on the journal entries recorded April 1 Tanner invested 80 000 cash along with office equipment valued at 26 000 in the company in exchange for common stock April 2 The company prepaid 9 000 cash for 12 months rent for office space The company s policy is to record prepaid expenses in balance sheet accounts April 3 The company made credit purchases for 8 000 in office equipment and 3 600 in office supplies Payment is due within 10 days April 6 The company completed services for a client and immediately received 4 000 cash April 9 The company completed a 6 000 project for a client who must pay within 30 days April 13 The company paid 11 600 cash to settle the account payable created April 3 April 19 The company paid 2 400 cash for the premium on a 12 month prepaid insurance policy The company s policy is to record prepaid expenses in balance sheet accounts April 22 The company received 4 400 cash as partial payment for the work completed on April 9 April 25 The company completed work for another client for 2 890 on credit April 28 The company paid 5 500 cash in dividends April 29 The company purchased 600 of additional office supplies on credit April 30 The company paid 435 cash for this month s utility bill Requirement General Journal General Ledger Trial Balance Income Statement St Retained Earnings Balance Sheet FS Impact General Journal Tab For each transaction prepare the required journal entry on the General Journal tab List debits before credits General Ledger Tab One of the advantages of general ledger software is that posting is done automatically To see the detail of all transactions that affect a specific account or the balance in an account at a specific point in time click on the General Ledger tab Check r

ning scenario mining company owns two mines each of which produces three grades high medium and low of ore The company has a contract to supply a smelting company with at least 12 tons of high grade ore at least 8 tons of medium grade ore and at least 24 tons of low grade ore Each hour of operation mine 1 produces 6 tons of high grade ore 2 tons of medium grade ore and 4 tons of low grade ore Each hour of operation mine 2 produces 2 tons of high grade ore 2 tons of medium grade ore and 12 tons of low grade ore It costs 200 per hour to operate mine 1 and 160 per hour to operate mine 2 How many hours should each mine be operated so as to meet the contractual obligations at the lowest total operating cost Microsoft Excel 16 0 Sensitivity Report 2 Worksheet 2 xlsx solution 3 Report Created 10 26 2019 7 20 34 PM 4 5 6 Variable Cells 7 8 Cell Name 853 X1 Hours to operate Mine 1 SCS3 X2 Hourse to operate Mine 2 9 10 11 12 Constraints 13 14 15 16 17 Cell Name SES6 High grade constraint LHS SE57 Medium grade constarint LHS SES8 Low grade constarint LHS Decrease Final Reduced Objective Allowable Allowable Value Cost Coefficient Increase 200 280 160 40 93 33333333 1 3 None of the above 0 0 Final Shadow Constraint Allowable R H Side Increase Value Price 12 8 40 10 70 0 12 8 24 8 4 16 40 Allowable Decrease 4 2 1E 30 Use this sensitivity report to answer the questions below If the cost per hour to operate Mine 1 was 300 Would 1 3 remain optimal What minimum Cost could be realized 1 3 will not remain optimal because 100 is not within the allowable increase of 40 1 3 will remain optimal because 100 is not within the allowable increase of 280 The minimum Cost will now be 780 1 3 will not remain optimal because 100 is not within the allowable increase of 280 1 3 will remain optimal because 100 is within the allowable increase of 280 The minimum Cost will now be 780

ign and low of ore mpany has a contract to supply a smelting company with at least 12 tons of high grade ore at least 8 tons of medium grade ore and at least 24 tons of low grade ore Each hour of operation mine 1 produces 6 tons of high grade ore 2 tons of medium grade ore and 4 tons of low grade ore Each hour of operation mine 2 produces 2 tons of high grade ore 2 tons of medium grade ore and 12 tons of low grade ore It costs 200 per hour to operate mine 1 and 160 per hour to operate mine 2 How many hours should each mine be operated so as to meet the contractual obligations at the lowest total operating cost D 1 Microsoft Excel 16 0 Sensitivity Report 2 Worksheet 2 xlsx solution 3 Report Created 10 26 2019 7 20 34 PM 4 5 6 Variable Cells 7 8 9 10 11 12 Constraints 13 14 Cell Name B 3 X1 Hours to operate Mine 1 C 3 X2 Hourse to operate Mine 2 Cell Name E 6 High grade constraint LHS SE 7 Medium grade constarint LHS 15 16 17 E 8 Low grade constarint LHS OOO Low grade High grade and Medium grade Medium grade Final Reduced Objective Allowable Allowable Value Cost Coefficient Increase Decrease High grade and Low grade 1 3 Use this sensitivity report to answer the questions below What constraints are binding at that optimal solution 12 8 40 0 0 Final Shadow Constraint Allowable Value Price R H Side Increase 200 160 10 70 0 12 8 280 40 93 33333333 24 8 4 16 Allowable Decrease 40 2 1E 30

In a large city school system with 35 elementary schools the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to be promoted to the next grade The PTA wants to find out whether parents agree with this plan Listed below are some of the ideas proposed for gathering data For parts a through d indicate what kind of sampling strategy is involved and what if any biases might result Assume the schools are homogeneous and differ from each other OC Bias could result only if the sampling strategy is not followed as described OD Nonresponse bias could result since not all parents will respond d Mail a survey to the home of every student and ask parents to fill it out and return it within a week Which kind of sampling strategy is involved OA Convenience sampling OB An attempt at a census OC Stratified sampling OD Cluster sampling What kind of bias if any is most likely to result OA Nonresponse bias could result since not all parents will respond OB Response bias could result since the PTA wants parents to agree to this plan OC Voluntary response bias will result since only parents who feel strongly about the issue will respond

An experiment investigates a dietary approach to treating anxiety disorder Researchers randomly assigned 29 subjects to two treatment groups one taking a high dose of vitamin c and the other a placebo Complete parts a and b below a Why was it important to randomize in assigning the subjects to the two groups A It eliminates the effects of unknown or uncontrollable sources of variation B It assures that the experiment is controlled C It should equalize the effects of unknown or uncontrollable sources of variation D It makes conditions as similar as possible for all treatment groups b What would be the advantages and disadvantages of using 100 subjects instead of 29 A It would take more time and be more controlled but random assignment is more difficult with more subjects B It would maximize the impact of individual variability in the responses but it would be a more costly and time consuming experiment C It would minimize the impact of individual variability in the responses but it would be a more costly and time consuming experiment OD It would assure that the subjects are randomly assigned but it would cause too much variability in the results

An experiment that showed that high doses of omega 3 fats might be of benefit to people with bipolar disorder involved a control group a Who are the individuals being studied The subjects for the experiment are What is the explanatory variable What is the response variable The explanatory variable is Are these variables categorical or quantitative Choose the correct answer below CICODE The response variable is OA The explanatory variable is quantitative while the response variable is categorical OB The explanatory variable is categorical while the response variable quantitative OC Both variables are categorical OD Both variables are quantitative b Why didn t the experimenters just give everyone the omega 3 fats to see if they improved Choose the correct answer below OA They need to compare omega 3 results to something OB They need to blind the participants OC They need to conserve omega 3 fats D Submit quiz subjects who received a placebo Complete parts a and b

Find y if xy yx y

Marcos purchases a top up card for his pre paid cell phone His remaining balance B can be modeled by the equation B 25 0 35n where n is the number of minutes he s talked since purchasing the card a How much money was on the card when he purchased it Select an answer C t Select an answer B intercept n intercept d when he runs out of money Which intercept is this minutes Which intercept is What are the units on the slope Select an answer O

0 3 4 9 1 1 2 Round all final answers to 2 decimal places a Q 1 b Med 2 c Q3 4 d IQR 3 e Identify the box plot for this data O 1 2 2 3 2 3 3 2 3 4 4 3 4 4 5 6 5 5 5 6 6 7 7 7 6 8 8 8 9 7 Q ta O O to O 9 a

The number of children in seven families looked like this 0 3 4 9 1 1 2 Round all final answers to 2 decimal places a Q b Med

Capacity and price data for a collection of USB flash drives is displayed in the table below Capacity Gb Price 8 9 99 16 11 99 32 17 99 64 26 99 128 48 99 256 86 99 x Use linear regression to find the best fit line for the data with capacity as the independent variable and price as the dependent variable y

The grades for a sample of 20 students on the most recent exam are given in the data table below Round yo answers to 2 decimal places as needed 88 49 69 83 67 69 91 90 72 98 Mean 75 8 52 84 93 Median 78 5 Standard deviation 65 75 94 85 82 57 53 Minimum score

250 people are asked how many siblings they have The incomplete results are shown below Please use 4 decimal places when apply of Siblings Frequency Relative Frequency Cumulative Frequency 0 59 1 2 3 4 44 57 48 0 236 0 176 0 228 0 192 59 101 145 202

The widths of platinum samples manufactured at a factory are normally distributed with a mean of 1 4 cm and a standard deviation of 0 1 cm Find the z scores that correspond to each of the following widths Round your answers to the nearest hundredth if necessary a 2 cm Z

A doctor gives some of the patients a new drug for treating acne and the rest of the patients receive the olc drug Neither the patient nor the doctor knows who is getting which drug Is this a blind experiment double blind experiment or neither Why O Double blind Neither the doctor or the patients know who is getting which drug Blind The doctor would know which drug the patient receives O Blind The patients would know which drug they receive ONeither Both the doctor and the patients would know who gets what drug

One group is told to exercise and one group is told to not exercise Is this a blind experiment double blind experiment or neither Why O Blind The groups are randomly selected O Double blind The members of one group would not know what the other group was doing Neither It is impossible for a group to not know whether they are exercising or not

43 87 of voters turned out for the 2004 elections Parameter Statistic

Determine whether the value is a parameter or statistic In a random sample of 90 students who passed statistics 65 used statistics in their future career Statistic O Parameter

Over a period of a few years the population of Denver increased It was observed that during this period the correlation between the number of people attending church and the number of people receiving traffic tickets was r 0 92 Does going to church cause people to get traffic tickets Is there a lurking variable that might cause both variables to increase O Going to church causes people to get traffic tickets O Getting traffic tickets causes people to go to church The increase in population is a lurking variable that caused both variables to increase

Match the name of the sampling method descriptions given de dividing the population by Gender and choosing 30 people of each gender b pulling 50 names from a hat casking people on the street randomly select two tables in the cafeteria and survey all the people at those two tables surveying every 3rd driver coming through a tollbooth e a Sampling Method Situations a Systematic b Simple Random c Convenience d Stratified

Are the following variables discrete or continuous a a person s age as listed on a driver s license discrete b the number of cars served at a fast food drive thru between noon and 2 pm continuo c The weights of elephants in captivity continuous

The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the eighth grade level In an earlier study the population proportion was estimated to be 0 22 How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 95 confidence level with an error of at most 0 037 Round your answer up to the next integer

At the local college a study found that students earned an average of 13 8 credit hours per semester A sample of 118 students was taken What is the best point estimate for the average number of credit hours per semester for all students at the local college 2 Daints Keypad

A fast food restaurant executive wishes to know how many fast food meals adults eat each week They want to construct a 90 confidence interval for the mean and are assuming that the population standard deviation for the number of fast food meals consumed each week is 1 4 The study found that for a sample of 1271 adults the mean number of fast food meals consumed per week is 3 Construct the desired confidence interval Round your answers to one decimal place Answer How to enter your answer opens in new window 2 Points Inner endpoint Keypad Keyboard Shortcuts

The electric cooperative needs to know the mean household usage of electricity by its non commercial customers in kWh per day They would like the estimate to have a maximum error of 0 15 kWh A previous study found that for an average family the standard deviation is 2 5 kWh and the mean is 15 9 kWh per day If they are using a 85 level of confidence how large of a sample is required to estimate the mean usage of electricity Round your answer up to the next integer

An environmentalist wants to find out the fraction of oil tankers that have spills each month Step 2 of 2 Suppose a sample of 313 tankers is drawn Of these ships 235 did not have spills Using the data construct the 80 confidence interval for the population proportion of oil tankers that have spills each month Round your answers to three decimal places Answer How to enter your answer opens in new window Lower endpoint Upper endpoint Keyp Keyboard Short Tables Previous step answ

Out of 178 randomly selected adults in the United States who were surveyed 77 exercise on a regular basis Construct a 95 confidence interval for the proportion of all adults in the United States who exercise on a regular basis Round to three decimal places Answer Lower endpoint Upper endpoint Keypad Keyboard Shortcut Tables

NASA is conducting an experiment to find out the fraction of people who black out at G forces greater than 6 In an earlier study the population proportion was estimated to be 0 4 How large a sample would be required in order to estimate the fraction of people who black out at 6 or more Gs at the 98 confidence level with an error of at mo 0 04 Round your answer up to the next integer Answer How to enter your answer opens in new window Tables Ke Keyboard Sh

An automotive manufacturer wants to know the proportion of new car buyers who prefer foreign cars over domestic Step 1 of 2 Suppose a sample of 3482 new car buyers is drawn Of those sampled 1253 preferred foreign over domestic cars Using the data estimate the proportion of new car buyers who prefer foreign cars Enter your answer as a fraction or a decimal number rounded to three decimal places Answer How to enter your answer opens in new window Tables Keypad Keyboard Shortcuts

A survey of 142 randomly selected students at one college showed that only 82 checked their campus email account on a regular basis Construct a 95 confidence interval for the percentage of students at the college who do not check their email account on a regular basis Round to one decimal place Answer Lower endpoint Upper endpoint Tables Keypa Keyboard Shortc

A software developer wants to know how many new computer games people buy each year A sample of 219 people was taken to study their purchasing habits Construct the 80 confidence interval for the mean number of computer games purchased each year if the sample mean was found to be 6 1 Assume that the population standard deviation is 1 5 Round your answers to one decimal place Answer How to enter your answer opens in new window Lower endpoint Upper endpoint Tables Keypad Keyboard Shortcu

A survey of 73 randomly selected homeowners finds that they spend a mean of 74 per month on home maintenance Construct a 95 confidence interval for the mean amount of money spent per month on home maintenance by all homeowners Assume that the population standard deviation is 16 per month Round to the nearest cent Answer Lower endpoint Upper endpoint Tables Keypad Keyboard Shortcuts

A research scientist wants to know how many times per hour a certain strand of bacteria reproduces He wants to construct the 99 confidence interval with a maximum error of 0 2 reproductions per hour Assuming that the mean is 9 6 reproductions and the standard deviation is known to be 2 2 what is the minimum sample size required for the estimate Round your answer up to the next integer Answer Tables Keyp

The mean amount of money spent on lunch per week for a sample of 75 students is 42 If the margin of error for the population mean with a 99 confidence interval is 2 10 construct a 99 confidence interval for the mean amount of money spent on lunch per week for all students Answer How to enter your answer opens in new window Lower endpoint Upper endpoint Tables Keypad Keyboard Shortcuts

The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day They would like the estimate to have a maximum error of 0 13 gallons A previous study found that for an average family the standard deviation is 1 3 gallons and the mean is 15 2 gallons per day If they are using a 85 level of confidence how large of a sample is required to estimate the mean usage of water Round your answer up to the next integer Answer How to enter your answer opens in new window Keypad Keyboard Shortcuts Tables

The mean GPA for 127 residents of the local apartment complex is 2 4 What is the best point estimate for the mean GPA for all residents of the local apartment complex Answer Keypa Keyboard Short Tables

A professor wants to estimate how many hours per week her students study A simple random sample of 65 students had a mean of 16 hours of studying per week Construct a 98 confidence interval for the mean number of hours a student studies per week Assume that the population standard deviation is known to be 2 4 hours per week Round to two decimal places Answer Lower Endpoint Upper Endpoint Tables Keypad Keyboard Shortcu

The mean per capita income is 23 037 dollars per annum with a variance of 149 769 What is the probability that the sample mean would be less than 23013 dollars if a sample of 134 persons is randomly selected Round your answer to four decimal places Answer How to enter your answer opens in new window 2 Points Keyp

Intelligence Quotient IQ scores are often reported to be normally distributed with 100 0 and 15 0 A random sample of 35 people is taken Step 1 of 2 What is the probability of a random person on the street having an IQ score of less than 95 Round your answer to 4 decimal places if necessa Answer Tables Keybc

The quality control manager at a computer manufacturing company believes that the mean life of a computer is 88 months with a variance of 81 If he is correct what is the probability that the mean of a sample of 84 computers would differ from the population mean by less than 1 39 months Round to four decimal places Answer 2 Tables your answer Keypad

Calculate the standard score z score of the given sample mean Round your answer to two decimal places 28 and G 8 n 67 3 27 Answer

The mean per capita consumption of milk per year is 126 liters with a standard deviation of 24 liters If a sample of 100 people is randomly selected what is the probability that the sample mean would be less than 122 27 liters Round your answer to four decimal places Answer Tables Keypad

A production manager at a wall clock company wants to test their new wall clocks The designer claims they have a mean life of 18 years with a standard deviation of 4 years If the claim is true in a sample of 49 wall clocks what is the probability that the mean clock life would be greater than 18 8 years Round your answer to four decimal places Answer Tables Keypad