Math Questions

You ask four people to the prom. If X is the number of "yes" responses, what is E(X)? Assume equal probability for "yes" and "no" response.

ATM passwords at a local bank consists of four digits. Paula remembers the first two digits of her password, but forgot the last two. What is the probably that Paula correctly guesses her password on the first try? 1/10000 1/100 1/10 1/1000

Suppose that the dollar value V (t) of a certain car that is f years old is given by the following exponential function. v (t) = 20,000 (1.16)^t Find the initial value of the car. Does the function represent growth or decay? growth decay By what percent does the value of the car change each year?

Julia just lit a new candle and then let it burn all the way down to nothing. The candle burned at a rate of 0.75 inches per hour and its initial length was 9 inches. Write an equation for L, in terms of t, representing the length of the candle remaining unburned, in inches, t hours after the candle was lit.

Which statements about a probability distribution are always true? The probability of an outcome is never 0. The expected value of a probability distribution is the mean of the distribution. The sum of the probabilities in a probability distribution is equal to 1. Values for for a discrete random variable X in a probability distribution are always positive. A probability distribution must have more than one outcome.

Suppose the probability that a pitcher throws a strike (the probability of success) is 0.5. What is the probability of the pitcher throwing a strike on the first attempt? 0 0.25 0.5 1

Determine the number and type of solutions for the equation 2x2 + 5x + 5 = 0 Two different irrational-number solutions One repeated irrational-number solution One repeated rational-number solution Two different rational-number solutions Two imaginary-number solutions

Which line is parallel to the line y = −4x+6 and passes through the point (-2, 5)? Write your answer as y=mx+b with no spaces. Use parenthesis if your slope is a fraction. For example, if your answer is y = −3x/4+1, you would type your answer as y=(-3/4)x+1

The number of users on a social networking site was 45 thousand in February when they officially went public and grew to 60 thousand by October. If the site is growing exponentially, and growth continues at the same rate, approximately how many users should they expect two years after they went public? 142 thousand 150 thousand 1420 thousand 107 thousand 90 thousand

Find all real solutions of the equation 3s² = 75. Write your answers as a list, using a comma to separate answers.

A study of elephants is conducted to determine the average weight of a certain subspecies of elephants. The standard deviation for the population is 1500 pounds. At a 99% level, how many elephants need to be weighed so the average weight will be accurate to within 350 pounds? 147 176 166 123

Ana dives into a pool off of a springboard high dive. Her height (in meters above the water), a seconds after diving, is modeled by h(x) = -5(x + 1)(x − 3) How many seconds after diving will Ana hit the water?

By completing the square, the expression x² + 12x + 87 equals (x + A)² + B where A = and B =

Squirrels are running wild on the campus, so Building and Grounds decides to tag 100 of them. In the spring, 50 squirrels are caught and 5 of them are tagged. What is the estimate for the number of squirrels living on campus?

A dance company charges $300 for a package of 20 dance lessons. Research shows that 20 percent of people attend all the lessons. The rest miss an average of 12 lessons. What is the expected value of a single dance for the company? $33.00 $28.00 $24.90 $31.00

In filing his income tax, Raul reported annual contributions of $300 to a public radio station, $180 to a public TV station, $200 to a local food bank, and $300 to other charitable organizations.

Enter values in the t-table for the piecwise function that is shown on the graph. Make sure that you are using the correct equation based for the x-value.

Because of the increasingly important role played by coal as a viable alternative energy source, the production of coal has been growing at the rate of 3.5e^0.05t billion metric tons/year, t years from 1980 (which corre sponds to t = 0). Had it not been for the energy crisis, the rate of production of coal since 1980 might have been only 3.5e^0.01t billion metric tons/year, t years from 1980. Determine how much additional coal was produced between 1980 and 2000 as an alternative energy source.

Amanda needs to buy some pencils. Brand A has a pack of 36 pencils for $8.52. Brand B has a pack of 48 pencils for $9.98. Find the unit price for each brand. Then state which brand is the better buy based on the unit price. Round your answers to the nearest cent.

Which line is perpendicular to the line y = 1/5 x - 1 and passes through the point (-2,-4)? Write your answer as y=mx+b with no spaces. Use parenthesis if your slope is a fraction. For example, if your answer is y=-3/4x+1. you would type your answer as y=(-3/4)x+1 -

Find all real solutions of the equation 9t²-7=29. Write your answers as a list, using a comma to separate answers.

Suppose 33.3% of high school students eat pizza and 42% drink soda. If 17.3% of high school students eat pizza and drink soda, what is the probability that a randomly chosen high school student will either eat pizza, drink soda, or both? 8.7% 58.0% 75.3% 92.6%

Suppose you invest $1,000 in an account paying 7% compounded annually. Assuming no other deposits or withdrawals, how many years would it take for the amount in the account to double to $2,000? Round to the nearest 10th

If the distance between the points (-5, − 3) and (x, 45) is 50 then the possible values for x are: List all possible values, separated by commas.

A tank that is 8 feet deep, with a square bottom with sides 4 feet each, has 1 foot of water that weighs 62.3 lb/ft³ in it. How much work, to the nearest whole unit (in ft-lb), will it take to pump the water to the rim of the tank?

The number of mosquitoes in Brooklyn (in millions of mosquitoes) as a function of rainfall (in centimeters) is modeled by m(x) = -2(x-4) What is the maximum possible number of mosquitoes?

Find the work done by a force F = 8i - 6j + 8k that moves an object from the point (0, 9, 9) to the point (7, 11, 19) along a straight line. The distance is measured in meters and the force in newtons.

Suppose that out of 100,000 male high school baseball players, only one-half percent make it to the Major Leagues. Find the expected number of male high school baseball players who make it to the Major Leagues. 500 50 5,000 100

Suppose that a family has 5 children. How could you simulate the probability of having a girl or boy using colns? What outcome would show the outcome of all girls? Let H represent having a girl and T represent having a boy: HHHHH Let H represent having a girl and T represent having a boy: TTTTT Let T represent having a girl and H represent having a boy; HHHHH Let T represent having a girl and H represent having a boy: HTTTH

Abby gets a job at a dress store that pays a salary of $90 per week plus $5 for each dress she sells.. a.) Write an equation to model this scenario. Use function notation. b.) If Abby sells 20 dresses, how much does she get paid? Show your work.

Which of the following is NOT a characteristic of the chi-square distribution? The chi-square curve approaches, but never touches, the positive horizontal axis. The mean of the chi-square distribution is located to the left of the peak. The chi-square curve is nonsymmetrical. As the degrees of freedom increases, the chi-square curves look more and more like a normal curve.

There are twelve songs on your playlist. Six of them are country and six are pop. With random shuffle and no repetition, you listen to six songs. What is the probability that you listened to all country songs?

In physics, work is defined as F D where F is the force applied over a distance of D. A box is dragged across 20 meters with a force of 60 Newtons, which are kg m/s2. What calculation will give us the work done, in Joules (which are kg m²/s2)? Choose 1 answer: 20.60 20.1000.60 20/1000.60 20/60

Consider the Quadratic function f(x) = 2x² - 9x - 35. Its vertex is ___, ____; its largest x-intercept is = _____, its y-intercept is y = ____

Consider the Quadratic function f(x) = 3x²-14x -24. Its vertex is its largest x-intercept is a = its y-intercept is y =

An economist wondered if people who go to the movies on weekdays go more or less often on Fridays than any other day. She figured that if it were truly random, 20% of these movie-goers would go on Fridays. She randomly sampled 50 people who go to movies on weekdays and asked them on which day they attend movies most frequently. Of those sampled, 14 indicated that they go on Fridays more often than other days. The economist conducts a one-proportion hypothesis test at the 5% significance level, to test whether the true proportion of weekday movie-goers who go most frequently on Fridays is different from 20%. For this test: Ho: p = .2, Ha: p≠2

How can you use a simulation with a number cube to collect data for an event that has two possible outcomes that each have a probability of 0.5? Select all that apply. Let the odd numbers represent one outcome and the even numbers represent the other outcome. Let numbers 1-3 represent one outcome and numbers 4-6 represent the other outcome. Let number 1 represent one outcome and number 6 represent the other outcome. Let numbers 1 and 2 represent one outcome and numbers 3-6 represent the other outcome. Let numbers 1-4 represent one outcome and numbers 5 and 6 represent the other outcome.

A parabola has a vertex at the point (-2, -3) and an x-intercept at (1, 0). Find the other x-intercept. You must justify your answer for credit.

A couple purchases a home with a $320,000 mortgage at 4% for 30 years with monthly payments. What will the remaining balance on their mortgage be after 10 years? $1527.73 $252,108.84 $213,333.33 $221,866.67 Can't be determined from the given information

A tile is drawn at random from the tiles below. What is the probability that it is a consonant and has a point-value that is less than 3? Write your answer as a fraction in simplest form.

A brand of jeans comes in nine different washes, five different fit styles, and three different height options. If two of the wash options are out of stock, how many ways can someone order a single pair of jeans? A. 95 B. 105 C. 120 D. 15

Captive primates, such as spider monkeys, often experience fractured bones. The probability distribution from a study of the X-rays of 500 captive spider monkeys shows that half of them had one healed fracture; one-quarter had two healed fractures; ten percent had three healed fractures; and fifteen percent had four healed fractures. About how many healed fractures would you expect a randomly selected captive spider monkey to have based on this probability distribution? 01 02 03 04

The function is defined as follows for the domain given. h(x) = 2x+1, domain = (-5, -1, 2, 3) Write the range of h using set notation. Then graph h.

Flight FL190 had 120 passenger seats, but 30% of these seats were empty. Therefore, passenger seats were occupied on the flight. 4 30 36 70 84

The diameters of apples from a certain farm follow the normal distribution with mean 4 inches and standard deviation 0.4 inch. Apples can be size-sorted by being made to roll over mesh screens. First the apples are rolled over a screen with mesh size 3.5 inches. This separates out of all the apples with diameters less than 3.5 inches. Second, the remaining apples are rolled over a screen with mesh size 4.3 inches. During that first step, what proportion of apples have a diameter of less than 3.5 inches? Round your answer to four decimal places.

Graph, label, and connect the following points: S(3, 2), D(6, 8), I(2, 8), and E(15, 2) to form polygon SIDE. a. Name the type of polygon. b. Find the length of the height. c. Find the area of the figure named SIDE. d. Calculate the lengths of segments SI and DE. e. Calculate the perimeter of SIDE. f. Find the slopes of SI and DE.

Find all real solutions of equation 3x² + 6x - 5 = 0. Does the equation have real solutions? Input Yes or No: If your answer is Yes, input the solutions:

Tiffany wants to calculate the volume of her globe. The globe is in the shape of a sphere, as represented in the picture. She measured the circumference of the globe along the equator to be 24 inches. Which of the following measures is closest to the volume of Tiffany's globe? A. 46 cubic inches B. 61 cubic inches C. 234 cubic inches D. 183 cubic inches

Graph y = |x-2|-3. [Hint: what is the vertex? How do you the vertex to plot the remaining points?]

A jet ski is travelling 75 degrees North of East at a constant speed of 43 miles per hour. The water is moving at a rate of 12 miles per hour due East. Represent the movement of the jet ski considering the wind. How far has the jet ski moved horizontally and vertically after 12 minutes?