A car battery manufacturer claims that its car batteries
Last updated: 4/19/2023
A car battery manufacturer claims that its car batteries last at least 3 5 years on average under normal operating conditions However many consumers have experienced battery failure well before 3 5 years A consumer advocacy group decided to investigate the company to determine if the company s claim about the average lifespan of their car batteries is exaggerated and misleading A random sample of 47 batteries was collected and tested by the consumer advocacy group and the mean lifespan was found to be 3 41 years Use the critical value method to test the hypothesis that the mean lifespan of this brand of car battery is less than 3 5 years using a 0 01 Assume that the standard deviation of the lifespans of all batteries produced by this company is known to be 0 29 years State the null and alternative hypothesis for this test Ho H Determine if this test is left tailed right tailed or two tailed Oright tailed two tailed left tailed Should the standard normal 2 distribution or Student s t distribution be used for this test The Student s distribution should be used The standard normal 2 distribution should be used Determine the critical value s for this hypothesis test Round the solution s to two decimal places If more than one critical value exists enter the solutions using a comma separated list Determine the test statistic Round the solution to two decimal places Determine the appropriate conclusion for this hypothesis test The sample data provide sufficient evidence to reject the alternative hypothesis that the mean lifespan of batteries produced by this company is less than 3 5 years and thus we conclude that the company s claim that the batteries last at least 3 5 years is likely true The sample data do not provide sufficient evidence to reject the null hypothesis that the mean lifespan of batteries produced by this company is at least 3 5 years and thus we conclude that the company s claim that the batteries last at least 3 5 years is likely true 1000 The sample data provide sufficient evidence to reject the null hypothesis that the mean lifespan of batteries produced by this company is at least 3 5 years and thus we conclude that the company s claim that the batteries last at least 3 5 years is likely false The sample data do not provide sufficient evidence to reject the alternative hypothesis that the mean lifespan of batteries produced by this company is less than 3 5 years and thus we conclude that the company s claim that the batteries last at least 3 5 years is likely false