A researcher is trying to identify if the mean return on a specific as

1.A researcher is interested in testing to determine if the mean of population one is greater than the mean of population two. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 items from population one resulting in a mean of 14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items from population two resulting in a mean of 11.8 and a standard deviation 2.9. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed, the degrees of freedom for this problem are _______.选项： A:15 B:22 C:2 D:23

2.A researcher is interested in testing to determine if the mean of population one is greater than the mean of population two. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 items from population one resulting in a mean of 14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items from population two resulting in a mean of 11.8 and a standard deviation 2.9. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed, the degrees of freedom for this problem are _______.选项： A:23 B:22 C:21 D:2

3.For an F distribution, the number of degrees of freedom for the numerator选项： A:must be larger than the number of degrees for the denominator B:must be smaller than the number of degrees of freedom for the denominator C:must be equal to the number of degrees of freedom for the denominator D:can be larger, smaller, or equal to the number of degrees of freedom for the denominator

4.For the hypothesis, H0: µ1 ≤ µ2, a random sample of 10 observations is selected from the first normal population and 8 from the second normal population. What is the number of degrees of freedom?选项： A:16; B:18; C:17; D:9

5.A researcher wants to conduct a before/after study on 11 subjects to determine if a treatment results in any difference in scores. The null hypothesis is that the average difference is zero while the alternative hypothesis is that the average difference is not zero. Scores are obtained on the subjects both before and after the treatment. After subtracting the after scores from the before scores, the average difference is calculated to be –2.40 with a sample standard deviation of 1.21. Assume that the differences are normally distributed in the population. The degrees of freedom for this test are _______.选项： A:11 B:10 C:9 D:20

6.In finding a confidence interval for the population mean, the population standard deviation should be used if it is known. If the population standard deviation is not known, then it should be estimated with _______.选项： A:the sample variance B:the sample standard deviation C:the range D:the mean

7. A portfolio has an expected mean return of 8% and standard deviation of 14%. The probability that its return falls between 8% and 11% is closest to: 选项： A: 8.5%. B: 14.8%. C: 58.3%.

8.According to the news item, Japan’s economic growth in the second quarter was ______ less than the first quarter. A．4 percentB．3 percentC．0.6 percentD．3.4 percent

9.Which of the following statements is INCORRECT?A、Spending by individuals in shops and on houses was very low.B、The annual growth rate in the second quarter is higher than the first quarter.C、Defence expenditure by the government is up 44 per cent on the previous year.D、AmericanE、conomists have different opinions on their country’s economic prospects.

10.A researcher is interested in testing to determine if the mean of population one is greater than the mean of population two. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 items from population one resulting in a mean of 14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items from population two resulting in a mean of 11.8 and a standard deviation 2.9. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed, the critical t-value from the table is _______.选项： A:1.323 B:1.721 C:1.717 D:1.321

11.A portfolio has an expected mean return of 8% and standard deviation of 14%. The probability that its return falls between 8% and 11% is closest to: 选项： A:A 8.5%. B:B 14.8%. C:C 58.3%.

12.Which of the following statements is most precise in introducing the economic development of China?选项： A:The economy of China advanced 6.4 percent year-on-year in the March quarter of 2019, slightly above market expectations of a 6.3 percent expansion.; B:GDP of China advanced almost the same in the March quarter of 2019 as in the previous quarter.; C:The growth rate of China’s GDP has been remaining above 6 percent this year.; D:China’s GDP advanced 6.4 percent year-on-year in the March quarter of 2019, the same pace as in the previous quarter but slightly above market expectations of a 6.3 percent expansion.

13.The standard deviation around an expected value is a useful measure of 选项： A、expected value of an asset. B、economic value of an asset. C、the difference between the best-case return of an asset and its worst-case return. D、deviation of an asset's actual returns from its expected returns.

14.Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes, and the population standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the probability that the mean time for the sample of 100 returns for this year is greater than 92? 选项： A:0.0832 B:Approximately 0 C:0.4168 D:0.0764

15.Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes, and the population standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the probability that the mean time for the sample of 100 returns for this year is greater than 92? 选项： A:0.0764 B:Approximately 0 C: 0.4168 D: 0.0832

16.If the degrees of freedom in a t-distribution become very large, _______. 选项： A:the t-values and the z-values are almost the same B:the sample size must be very small C:the population size must be very large D:the sample mean approaches zero

17.If the degrees of freedom in a t-distribution become very large, _______. 选项： A:the t-values and the z-values are almost the same B:the population size must be very large C:the sample mean approaches zero D:the sample size must be very small

18.If the degrees of freedom in a t-distribution become very large, _______.选项： A:the t-values and the z-values are almost the same B:the population size must be very large C:the sample mean approaches zero D:the sample size must be very small

19.Given the following information, calculate the degrees of freedom that should be used in the pooled-variance t test. S12 = 4 S22 = 6 n1 = 16 n2 = 25选项： A:df = 41; B:df = 39; C:df = 16; D:df = 25

20. A statistical measure of the variability of a distribution around its mean is referred to as the:LO7.4 选项： A: standard deviation. B: expected return. C: median. D: coefficient of variation.

21. Neap tides occur when the ______．选项： A:Moon is in its first quarter and third quarter phases B:Sun and Moon are on opposite sides of the Earth C:Moon's declination is maximum and opposite to that of the Sun D:Sun and Moon are in conjunction

22.Suppose that the distribution of a set of scores has a mean of 47 and a standard deviation of 14. If 4 is added to each score, what will be the mean and the standard deviation of the distribution of new scores? 选项： A: mean 51   Standard Deviation 14; B: mean 51   Standard Deviation 18; C: mean47  Standard Deviation 14; D: mean47   Standard Deviation16

23.In testing for differences between the means of two related populations where the variance of the differences is unknown, the degrees of freedom are:选项： A:n - 1. B:n1 + n2 - 1 C:n1 + n2 - 2 D:n - 2

24.An experimenter has conducted a single-factor experiment with four levels of the factor, and each factor level has been replicated 5,6,7,8 times respectively. How many degrees of freedom does the sum of squared errors has?选项： A:22; B:23; C:25; D:26