- Question: (CO 5) A company claims that its heaters last more than 5 years. Write the null and alternative hypotheses and note which is the claim.
- Question: (CO 5) An executive claims that her employees spend no more than 2.5 hours each week in meetings. Write the null and alternative hypotheses and note which is the claim.
- Question: (CO 5) In hypothesis testing, a key element in the structure of the hypotheses is that the null hypothesis has the
- Question: (CO 5) A landscaping company claims that at most 90% of workers arrive on time. If a hypothesis test is performed that fails to reject the null hypothesis, how would this decision be
interpreted?
- Question: (CO 5) A textbook company claims that their book is so engaging that less than 55% of students read it. If a hypothesis test is performed that fails to reject the null
hypothesis, how would this decision be interpreted?
- Question: (CO 5) An advocacy group claims that the mean braking distance of a certain type of tire is 75 feet when the car is going 40 miles per hour. In a test of 80 of these tires, the braking distance has a mean of 77 and a standard deviation of 5.9 feet. Find the standardized test statistic and the
corresponding p-value.
- Question: (CO 5) The heights of 82 roller coasters have a mean of
281.4 feet and a standard deviation of 59.3 feet. Find the standardized tests statistics and the corresponding p-value when the claim is that roller coasters are less than 290 feet tall.
- Question: (CO 5) A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 720 hours. A random sample of 51 light bulbs as a mean of 705.4 hours with a population standard deviation of 62 hours. At an α=0.05, can you support the company’s claim using the test statistic?
- Question: (CO 5) A restaurant claims the customers receive their food in less than 16 minutes. A random sample of 39 customers finds a mean wait time for food to be 15.8 minutes with a population standard deviation of 0.7 minutes. At α = 0.04, can you support the organizations’ claim using the test statistic?
- Question: (CO 5) A manufacturer claims that their calculators are 6.800 inches long. A random sample of 55 of their calculators finds they have a mean of 6.812 inches with a standard deviation of 0.05 inches. At α=0.08, can you support the manufacturer’s claim using the p value?
- Question: (CO 5) A travel analyst claims that the mean room rates at a three-star hotel in Chicago is greater than $152. In a random sample of 36 three-star hotel rooms in Chicago, the mean room rate is $165 with a population standard deviation of $41. At α=0.10, can you support the analyst’s claim using the p-value?
- Question: (CO 5) A car company claims that the mean gas mileage for its luxury sedan is at least 24 miles per gallon. A random sample of 7 cars has a mean gas mileage of 23 miles per gallon and a standard deviation of 1.1 miles per gallon. At α=0.05, can you support the company’s claim assuming the population is normally distributed?
- Question: (CO 5) A state Department of Transportation claims that the mean wait time for various services at its different location is more than 6 minutes. A random sample of 16 services at different locations has a mean wait time of 9.5 minutes and a standard deviation of 7.3 minutes. At α=0.05, can the department’s claim be supported assuming the population is normally distributed?
- Question: (CO 5) A used car dealer says that the mean price of a three- year-old sport utility vehicle in good condition is $18,000. A random sample of 20 such vehicles has a mean price of
$18,450 and a standard deviation of $1050. At α=0.08, can the dealer’s claim be supported assuming the population is normally distributed?
- Question: (CO 5) A researcher wants to determine if eating more vegetables helps high school juniors learn algebra. A junior class is divided into pairs and one student from each pair has extra vegetables and the other in the pair does not. After 2 weeks, the entire class takes an algebra test and the results of the two groups are compared. To be a valid matched pair test, what should the researcher consider in creating the two groups?
- Question: (CO 5) Assuming the population is normally distributed, test the claim that the mean is more than 23 using an α of 0.05. The sample statistics are a mean of 24.9, standard deviation
of 2.11, and an n of 9.
- Question: (CO 5) A company claims that the hold times for customer service averages at most 10 minutes. A random sample of 24 hold times has a mean of 11.2 minutes with a standard deviation of 7.2 minutes. Is there enough evidence to support the claim at α = 0.05? Assume the population is
normally distributed.
- Question: (CO 5) A coach claims that all players can run more than 1.5 miles. A random sample of 17 players finds that they can run an average of 1.7 miles with a standard deviation of 0.4 miles. Is there enough evidence to support the claim at α of 0.01? Assume the population is normally distributed.
Instituition / Term | |
Term | Summer 2021 |
Institution | MATH 221 Statistics for Decision-Making |
Contributor | Rizelle |