Which of the following statements is true about the t-distribution?    a) For large sample sizes, the t-distribution has the same properties as the normal curve. b) For small sample sizes, the t-distribution has the same properties as the normal curve.   c) Like the Normal distribution, the t-distribution is symmetric for small n. d) Since population standard deviation is usually unknown, the standard error uses the sample standard deviation to estimate population standard deviation.

A study was done on body temperatures of men and women. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. State the conclusion for the test. Use a 0.01 significance level to test the claim that men have a higher mean body temperature than women. μ n X S Men 11 11 97.53°F 0.76°F Women H₂ 59 97.46°F 0.69°F O A. Reject the null hypothesis. There is not sufficient evidence to support the claim that men have a higher mean body temperature than women. OB. Fail to reject the null hypothesis. There is sufficient evidence to support the claim that men have a higher mean body temperature than women. OC. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that men have a higher mean body temperature than women. OD. Reject the null hypothesis. There is sufficient evidence to support the claim…

10)   A county is considering raising the speed limit on a road because they claim that the mean speed of vehicles is greater than 40 mi/hr. A random sample of 15 vehicles has a mean speed of 43 mil/hr and a standard deviation of 4.4 mi/hr.   Assume that speeds follow a normal distribution. What statistical test should be used to test the claim?  (pick one of the options) 1. t-test 2. 2.73 3. 15 4. 10.9 5. 14 6. z-test 7. 2.52 8. 2.64 Calculate the value of standardized test statistic.  (pick one of the options) 1. t-test 2. 2.73 3. 15 4. 10.9 5. 14 6. z-test 7. 2.52 8. 2.64 What is the degree of the freedom for the distribution of the test statistics. (pick one of the options) 1. t-test 2. 2.73 3. 15 4. 10.9 5. 14 6. z-test 7. 2.52 8. 2.64

Which of the following are true? There is more than one correct answer.

A study was done on body temperatures of men and women. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. State the conclusion for the test. Use a 0.01 significance level to test the claim that men have a higher mean body temperature than women. μ n X S Men H₁ 11 97.66°F 0.75°F Women H₂ 59 97.22°F 0.68°F O A. Reject the null hypothesis. There is not sufficient evidence to support the claim that men have a higher mean body temperature than women. O B. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that men have a higher mean body temperature than women. O C. Reject the null hypothesis. There is sufficient evidence to support the claim that men have a higher mean body temperature than women. O D. Fail to reject the null hypothesis. There is sufficient evidence to support the…

The grade point average for ALL juniors at a large college has a standard deviation of 0.50.  A random sample of 20 students is to be used to estimate the population mean grade point average.  What condition do you need to verify prior to computing the probability of obtaining a sample mean within plus or minus 0.2 of the population mean?

A standardized test for graduate school admission has a mean score of 159 with a standard deviation of 8 and a​ unimodal, symmetric distribution of scores. A test preparation organization teaches small classes of 4 students at a time. A larger organization teaches classes of 64 at a time. Both organizations publish the mean scores of all their classes. A mean score of 167 is SD _____ above the mean for the smaller​ organization, and ______ SD above the mean for the larger organization. It is more likely that the smaller organization will have that success.

The t distribution should be used whenever: Select one: A. the population is not normally distributed. B. the sample standard deviation is used to estimate the population standard deviation. C. None of the answers are correct. D. the sample size is less than 30.

Are the mean number of times a month a person eats out the same for whites, blacks, Hispanics and Asians? Suppose that the table below shows the results of a study. White Black Hispanic Asian 5 4 8 9 8 1 3 3 2 5 5 5 4 2 4 1 6   6 7 Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05. (Let 1 = White, 2 = Black, 3 = Hispanic, and 4 = Asian.) Part (a) State the null hypothesis. H0: ?1 = ?2 = ?3 = ?4 H0: At least two of the group means ?1, ?2, ?3, ?4, are not equal.      Part (b) State the alternative hypothesis. Ha: At least two of the group means ?1, ?2, ?3, ?4, are not equal. Ha: ?1 = ?2 = ?3 = ?4      Part (c) Enter an exact number as an integer, fraction, or decimal. df(num) =  Part (d) Enter an exact number as an integer, fraction, or decimal. df(denom) =  Part (e) State the…