The paper "The Effects of Adolescent Volunteer Activities on the Perception of Local Society and Community Spirit Mediated by Self-Conception describes a survey of a large representative sample of middle school children in South Korea. One question in the survey asked how much time per year the children spent in volunteer activities. The sample mean was 14.76 hours and the sample standard deviation was 16.54 hours. LAUSE SALT (a) Based on the reported sample mean and sample standard deviation, explain why it is not reasonable to think that the distribution volunteer times for the population of South Korean middle school students is approximately normal. (Round your answer to nearest percent.) ✔% of volunteer times would be negative. Therefore, it is not If the distribution of volunteer times is approximately normal, for the sample standard deviation of s-16.54 hours and the sample mean of x- 14.76 hours, approximately 19 distribution of volunteer times is approximately normal. reasonable to think that the (b) The sample size was not given in the paper, but the sample size was described as large. Suppose that the sample size was 700. Explain why it is reasonable to use a one-sample t confidence interval to estimate the population mean even though the population distribution is not approximately normal. (Select all that apply.) It is reasonable to use a one-sample : confidence interval to estimate the population mean since the sample size is at most 30. It is reasonable to use a one-sample : confidence interval to estimate the population mean since the sample size is at least 30. It is reasonable to use a one-sample t confidence interval to estimate the population mean since the sample is representative of the population. It is reasonable to use a one-sample t confidence interval to estimate the population mean since the statistics came from a paper. It is reasonable use a one-sample t confidence interval to estimate the population mean since all of the middle school children in South Korea were surveyed. (c) Calculate a 95% confidence interval (in hours) for the mean number of hours spent in volunteer activities per year for South Korean middle school children. (Round your answers to three decimal places.) (15.985x13.535 x ) hrs Interpret the interval. O There is a 95% chance that the true mean number of hours spent in volunteer activities per year for South Korean middle school children falls directly in the middle of this interval. O There is a 95% chance that the number of hours spent in volunteer activities per year for South Korean middle school children falls within this interval. We are 95% confident that the true mean number of hours spent in volunteer activities per year for South Korean middle school children falls within this interval. We are 95% confident that the number of hours spent in volunteer activities per year for South Korean middle school children falls within this interval. There is a 95% chance that the number of hours spent in volunteer activities per year for South Korean middle school children falls directly in the middle of this interval.

Fuel efficiency of Prius:  Fueleconomy.gov, the official US government source for fuel economy information, allows users to share gas mileage information on their vehicles. The histogram below shows the distribution of gas mileage in miles per gallon (MPG) from 14 users who drive a 2012 Toyota Prius. The sample mean is 53.3 MPG and the standard deviation is 5.2 MPG. Note that these data are user estimates and since the source data cannot be verified, the accuracy of these estimates are not guaranteed. (a) The EPA claims that a 2012 Prius gets 50 MPG (city and highway mileage combined). Do these data provide strong evidence against this estimate for drivers who participate on fueleconomy.gov? The test statistic is: __________________(please round to two decimal places)The p-value:___________________________ for this hypothesis test is:  (please round to four decimal places)(c) Please comment on the primary thing that is wrong about the following statement: There is sufficient evidence…

A report about how American college students manage their finances includes data from a survey of college students. Each person in a representative sample of 793 college students was asked if they had one or more credit cards and if so, whether they paid their balance in full each month. There were 500 who paid in full each month. For this sample of 500 students, the sample mean credit card balance was reported to be $825. The sample standard deviation of the credit card balances for these 500 students was not reported, but for purposes of this exercise, suppose that it was $205. Is there convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than $907, the value reported for all college students with credit cards? Carry out a hypothesis test using a significance level of 0.01.   State the appropriate null and alternative hypotheses. H0: ? = 907 Ha: ? < 907 H0: ? = 907 Ha: ? > 907      H0: ? < 907…

Airline companies are interested in the consistency of the number of babies on each flight, so that they have adequate safety equipment. They are also interested in the variation of the number of Babies. Suppose that an airline executive believes the standard deviation in the number of babies is 6 at the most. The airline conducts a survey. The results of the 23 flights surveyed give a samle mean of 8 with a sample standard deviation of 9. Test the executive's belief to see if it is accurate, or if it is actually greater at the a = 0.05 level. Ho:o = H:o Select an answer df = P-value = The p-value is... greater than a less than (or equal to) a This test statistic leads to a decision to... reject the null fail to reject the null accept the alternative accept the null As such, the final conclusion is that there Select an answer v sufficient evidence to conclude the standard deviation of the number of babies on airplanes is Select an answer than (?

1) According to Consumer Expenditures, the average consumer spent $1729 on apparel and services in 2017. In 2018, a random sample of 36 consumers had a mean of $1667.11 and a standard deviation of $351.69. Can it be said that at the 5% level of significance that the mean level of consumption differed in 2018 with respect to 2017?

The average credit card debt for a recent year was $8,776. Five years earlier the average credit card debt was $8,189. Assume sample sizes of 32 were used and the population standard deviations of both samples were $690. Is there evidence to conclude that the average credit card debt has increased?

In a sample of 351 gamers between the ages of 16-25, the mean number of hours spent gaming per week was 42.5 hours. In a sample of 269 gamers between the ages of 26-40, the mean number of hours spent gaming per week was 43.8 hours. If the population standard deviation for the mean number of hours spent gaming per week is 9.5 for the age group 16-25 and 10.7 for the age group 26-40, test the claim that gamers between the ages of 16-25 spend less time gaming per week than gamers between the ages of 26-40. Assume α=0.03.      Let population 1 be gamers in the age group 16-25 and population 2 be gamers in the age group 26-40. Round the test statistic to two decimal places, and round the p-value to four decimal places.   The test statistic is . The p-value is . Should the null hypothesis be rejected?