A pipes manufacturer makes pipes with a length that is supposed to be 16 inches. A quality control technician sampled 29 pipes and found that the sample mean length was 16.05 inches and the sample standard deviation was 0.14 inches. The technician claims that the mean pipe length is not 16 inches.   What type of hypothesis test should be performed? What is the test statistic?

Bone mineral density (BMD) is a measure of bone strength. Studies show that BMD declines after age 45. The impact of exercise may increase BMD. A random sample of 59 women between the ages of 41 and 45 with no major health problems were studied. The women were classified into one of two groups based upon their level of exercise activity: walking women and sedentary women. The 39 women who walked regularly had a mean BMD of 5.96 with a standard deviation of 1.22. The 20 women who are sedentary had a mean BMD of 4.41 with a standard deviation of 1.02. Which of the following inference procedures could be used to estimate the difference in the mean BMD for these two types of women

The amount of water consumed each week by Bronx residences is normally distributed. The population mean of water consumption is 120.3 gallons with a standard deviation of 10.0 gallons. Test the claim at the 0.10 significance level that the average amount of water consumed is not 125 gallons with a sample size of 100 residences.   Do you retain or reject the null hypothesis?

Historically, evening long-distance calls from a particular city have averaged 15.1 minutes per call. In a random sample of 37 calls, the sample mean time was 13.3 minutes. Assume the standard deviation is known to be 5 minutes. Using a 0.05 level of significance, is there sufficient evidence to conclude that the average evening long-distance call has decreased?

1 Jump to level 1 A pipes manufacturer makes pipes with a length that is supposed to be 11 inches. A quality control technician sampled 32 pipes and found that the sample mean length was 11.09 inches and the sample standard deviation was 0.2 inches. The technician claims that the mean pipe length is not 11 inches. What type of hypothesis test should be performed? Select What is the test statistic? Ex: 0.123 What is the number of degrees of freedom? Ex: 20 Does sufficient evidence exist at the a= 0.05 significance level to support the technician's claim? Select Check HIN 60°F

According to a survey, the average American person watches TV for 3 hours per week. To test if the amount of TV in New York City is more than the national average, a researcher decides to do a hypothesis test, at a 1% significance level. She surveys 23 New Yorkers randomly and asks them about their amount of TV each week, on average. From the data, the sample mean time is 3.8 hours per week, and the sample standard deviation (s) is 1.1 hours. H0: μ≤3; Ha: μ>3. α=0.01 (significance level) What is the test statistic (t-value) of this one-mean hypothesis test (with σ unknown)? Round your final answer to two decimal places. Provide your answer below:   $$Test Statistic =

A pipes manufacturer makes pipes with a length that is supposed to be 12 inches. A quality control technician sampled 35 pipes and found that the sample mean length was 12.05 inches and the sample standard deviation was 0.13 inches. The technician claims that the mean pipe length is not 12 inches. What type of hypothesis test should be performed? Two-tailed t-test Two-tailed z-test Left tailed t-test Left tailed z-test What is the test statistic? What is the number of degrees of freedom? Does sufficient evidence exist at the α=0.01 significance level to support the technician's claim? Yes or No

Using traditional methods, it takes 98 hours to receive a basic driving license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique with 270 students and observed that they had a mean of 97 hours. Assume the standard deviation is known to be 7. A level of significance of 0.1 will be used to determine if the technique performs differently than the traditional method. Is there sufficient evidence to support the claim that the technique performs differently than the traditional method? What is the conclusion?

A professional racing team is holding tryouts at its test track. The team requires its drivers to have an average lap time of at most 133 seconds at its test track. The team will use a one sample z-test of significance to determine if they should hire a new driver.   An amateur driver completes 8 timed laps of the test track with an average lap time of 136 seconds. If the standard deviation of all lap times at this track is 4.1 seconds, what is the value of the test statistic? Round your answer to two decimal places.

An article in the San Jose Mercury News stated that students in the California state university system take 6 years, on average, to finish their undergraduate degrees. A freshman student believes that the mean time is less and conducts a survey of 53 students. The student obtains a sample mean of 4.1 with a sample standard deviation of 1.9. Is there sufficient evidence to support the student's claim at an �=0.1 significance level? Test the claim: Determine the null and alternative hypotheses. Enter correct symbol and value.�0: �=Incorrect��: �    Correct< Incorrect Determine the test statistic. Round to four decimal places.�=Incorrect Find the �-value. Round to 4 decimals.