The authors of a certain paper describe a study to evaluate the effect of mobile phone use by taxi drivers in Greece. Fifty taxi drivers drove in a driving simulator where they were following a lead car. The drivers were asked to carry on a conversation on a mobile phone while driving, and the following distance (the distance between the taxi and the lead car) was recorded. The sample mean following distance was 3.40 meters and the sample standard deviation was 1.11 meters. (a) Construct a 95% confidence interval (in meters) for u, the population mean following distance while talking on a mobile phone for the population of taxi drivers. (Use a table or technology. Round your answers to three decimal places.) 3077 X-3.719 Interpret the interval, There is a 95% chance that the true mean following distance while talking on a mobile phone for the population of taxi drivers falls directly in the middle of this interval O We are 95% confident that the following distance while talking on a mobile phone for the population of taxi drivers falls within this interval O We are 95% confident that the true following distance while talking on a mobile phone for the population of taxi drivers falls within this interval There is a 95% chance that the following distance while talking on a mobile phone for the population of taxi drivers falls directly in the middle of this interval There is a 95% chance that the following distance while taking on a mobile phone for the population of taxi drivers falls within this interval

1. The fuel efficiency of a new model pick-up truck (truck) is measured in miles per gallon (mpg). A company claims that their new truck gets 25 mpg on average. A consumer group thinks the company is lying and claims that the mean mileage for all the trucks is less than 25 mpg. In a random sample, of forty-five of these trucks the mean mpg was 23.3 mpg with a standard deviation of 5.1 mpg. a. Conduct a hypothesis test to test the consumer group's claim at the 5% significance level. Be sure to state you Ho and Ha, your test statistic and p- value, whether or not you reject Ho and whether you support the claim. b. Write a complete sentence describing what a Type I error is in context. c. Write a complete sentence describing what a Type II error is in context.

A sample of 76 female workers and another sample of 48 male workers from a state produced mean weekly earnings of $743.50 for the females and $777.63 for the males. Suppose that the population standard deviations of the weekly earnings are $80.05 for the females and $88.68 for the males. The null hypothesis is that the mean weekly earnings are the same for females and males, while the alternative hypothesis is that the mean weekly earnings for females is less than the mean weekly earnings for males. Directions: • Label your answers with the correct statistical symbols. • If you use the Ti, identify which function and values you used to calculate. If you solve by hand, show all steps 2.5 The significance level for the test is 1%. What is/are the critical value(s)? 2.6. What is the value of the test statistic, rounded to three decimal places? 2.7. What is the p-value for this test, rounded to four decimal places? 2. 8. Using the p-value approach, do you reject or fail to reject the null…

. Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout. Suppose a friend tells you that the average length of trout caught in Pyramid Lake is ? = 19 inches. However, the Creel Survey reported that of a random sample of 49 fish caught, themean length was ?̅= 18.5 inches, with estimated standard deviation ? = 3.2 inches. Do these data indicate that the average length of a trout caught in Pyramid Lake is less than ? = 19 inches? Use ? = 0.05.a. Do we use a Normal or a Student’s t- distribution? Explain. How many degrees of freedom do we use?b. What are the hypotheses?

A local church parish wants to raise money to add to their campus. In a sample from a previous fund raising campaign, the parish found that of the 131 people in the sample they contacted, that 69 actually contributed money. Of those that contributed money, the average contribution was $857 with a standard deviation of $265. In the recent fundraising campaign, a sample of 95 people revealed that 48 have contributed money with an average contribution of $1109 and a standard deviation of $339. When testing (at the 5% level of significance) whether the average amount contributed has increased in the current campaign compared to the previous campaign, what is the test statistic? (please round your answer to 2 decimal places)

Beer Drinking. The mean annual consumption of beer per person in the US is 22.0 gallons . A random sample of 300 Washington D.C. residents yielded a mean annual beer consumption of 27.8 gallons. At the 10% significance level, do the data provide sufficient evidence to conclude that the mean annual consumption of beer per person for the nation’s capital differs from the national mean? Assume that the standard deviation of annual beer consumption for Washington D.C. residents is 55 gallons.

A study was conducted for an aviation safety agency in which they surveyed thousands of passengers at airports across Europe. In this study, the "mass" for a passenger includes the weight of the passenger and all of the passenger's carry-on items, including infants without their own seats. For the 5,904 adult male passengers measured in summer, the sample mean and standard deviation for this mass were 88.8 kg and 15.9 kg, respectively.   (a) Construct a 95% confidence interval (in kilograms) for the population mean mass for adult male passengers in summer. (Round your answers to three decimal places.) ___to__ kg (b) Write a sentence or two interpreting the confidence interval you found in part (a). With 95% confidence, we can estimate that the population mean mass of male passengers traveling in the summer is contained within the interval. We can estimate that 95% of the male passengers traveling in the summer in the sample have a mass that is contained within the interval.…

Christin ently switched her primary doctor to one specializing in caring for elderly patients. On her new doctor's website, it says that the mean systolic blood pressure among elderly females is 115 millimeters of mercury (mmHg). Christine believes the value is actually higher. She bases her belief on a recently reported study of 14 randomly selected, elderly females. The sample mean systolic blood pressure was 129 mmHg, and the sample standard deviation was 22 Español mmHg. Assume that the systolic blood pressures of elderly females are approximately normally distributed. Based on the study, at the 0.05 level of significance, can it be concluded that u, the population mean systolic blood pressure among elderly females, is greater than 115 mmHg? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.) (a) State the null hypothesis H and the alternative hypothesis H . H, :0…

According to the Bureau of Labor Statistics, the mean salary for registered nurses in Kentucky was $55,130. The distribution of salaries is assumed to be normally distributed with a standard deviation of $5,778. Someone would like to determine if registered nurses in Ohio have a greater average pay. To investigate this claim, a sample of 220 registered nurses is selected from the Ohio Board of Nursing, and each is asked their annual salary. The mean salary for this sample of 220 nurses is found to be $55,504.488.  Completely describe the sampling distribution of the sample mean salary when samples of size 220 are selected. mean:  μ x-bar = ____ standard deviation: σ x-bar  = ____ shape: the distribution of is ____________(not normally distributed/normally distributed) because ___________ (the sample size is large/the sample size is not large/the population of salaries is normally distributed/the population of salaries is not normally distributed)