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Experiments on animal learning often measure how long a mouse takes to get through a maze. For one particular maze, the true mean time is 18 seconds. A researcher thinks that a loud noise will help the mice to complete the maze faster. She measures the average time, x-bar, required for 10 mice to complete the maze when the loud noise is played. Which is a suitable null hypothesis in this situation?

Gasoline pumped from a supplier’s pipeline is supposed to have an octane rating of 87.5. For 13 consecutive days, a liter of gas from the pipeline was obtained and analyzed. The resulting octane readings for these 13 days are given below:88.6     86.4     87.2     88.4     87.2     87.6     86.8     86.1     87.4     87.3     86.4     86.6     87.1Here is the data set in StatCrunch. The supplier wants to test the claim that the octane reading from the pipeline has a true mean that is less than 87.5 at the 5% level of significance.Are the results of the test statistically significant?

Gasoline pumped from a supplier’s pipeline is supposed to have an octane rating of 87.5. For 13 consecutive days, a liter of gas from the pipeline was obtained and analyzed. The resulting octane readings for these 13 days are given below:88.6     86.4     87.2     88.4     87.2     87.6     86.8     86.1     87.4     87.3     86.4     86.6     87.1Here is the data set in StatCrunch. The supplier wants to test the claim that the octane reading from the pipeline has a true mean that is less than 87.5 at the 5% level of significance. State the null and alternative hypothesis for this situation and the type of tail.

Public Policy Polling (PPP), a reputable polling company, asked the following question in a previous Halloween-eccentric public opinion poll:“If zombies took over the world and human civilization collapsed, how long do you think you could survive: less than one week, less than one month, less than six months, less than one year, or more than a year?” Of the 1,200 likely voters who were asked this question, 324 said “Less than one week”. Construct a 99% confidence interval for the true population percentage of likely voters who said that they would survive a zombie apocalypse for less than one week. Round to three decimal places.

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 30 minutes. The owner has randomly selected 50 customers and has delivered pizzas to their homes in order to test if the mean delivery time does not exceed 30 minutes. Suppose the p-value for the test was found to be 0.0287. State the correct conclusion at the significance level of 0.01.

This following is the print out for the variable, DISTANCE_2, from the MAT 131 Student Survey. This variable was the responses for the question, “What is the distance (in miles) from your home to the College?”. Assume that the sample is representative of all students taking Statistics 1 at Cincinnati State. 95% confidence interval results: Variable Sample Mean Std. Err. DF L. Limit U. Limit DISTANCE_2 13.872011 0.82889538 183 12.23659 15.507431 Is it likely that true mean distance from home to College for all students at Cincinnati State taking MAT 131 is greater than 20 miles? Explain.

Would the standard error likely get larger or smaller if the sample size were increased? Explain.

This following is the print out for the variable, DISTANCE_2, from the MAT 131 Student Survey. This variable was the responses for the question, “What is the distance (in miles) from your home to the College?”. Assume that the sample is representative of all students taking Statistics 1 at Cincinnati State. 95% confidence interval results: Variable Sample Mean Std. Err. DF L. Limit U. Limit DISTANCE_2 13.872011 0.82889538 183 12.23659 15.507431 What is the margin of error for this confidence interval? Round to two decimal places.

A researcher wants to determine if the average cholesterol level in his city is different from the national average of 195. Draw a conclusion about the cholesterol levels in the research’s city at the significance level of 0.01. Test of Ho:  μ = 195 vs H1:  μ ≠ 195n     Mean    T-stat    p-value 50   198       1.77       0.0768

Suppose a 95% confidence interval for the population proportion of American adults who exercise regularly is 0.29 to 0.37. Which one of the following statements is FALSE?