智慧树知到《商务统计》2023见面课答案

1、 One rule that must always be followed in constructing frequency distributions is that __.

A.adjacent classes must not overlap

B.the midpoint of each class must be a whole number

C.the width of each class is equal to the range

D.the number of intervals must be an odd number

正确答案：adjacent classes must not overlap

2、A.are established correctly

B.are not mutually exclusively

C.are not collectively exhaustive

D.don not reference a population parameter

正确答案：are not collectively exhaustive

3、When a false null hypothesis is not rejected, the researcher has made a

A. type II error.

B. sampling error.

C.powerful error.

D. type I error

正确答案： type II error.

4、A.

B.

C.

D.

正确答案：

5、Which of the following is an appropriate null hypothesis?

A.

B.

C.

D.

正确答案：

6、In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves?

A.a test for the equality of variances from 2 independent populations

B.a test for the difference between the means of 2 related populations

C.a test for the difference between the means of 2 independent populations

D.All of the above

正确答案：All of the above

7、The test for the equality of two population variances is based on the

A.ratio of the two sample variances

B.difference between the two sample variances

C.difference between the two population variances

D.difference between the sample variances divided by the difference between the sample means

正确答案：ratio of the two sample variances

8、A.zero.

B.-0.5.

C.0.5

D.one.

正确答案：0.5

9、A.t distribution with 73 degrees of freedom

B. t distribution with 72 degrees of freedom.

C.t distribution with 71 degrees of freedom

D. t distribution with 70 degrees of freedom.

正确答案： t distribution with 70 degrees of freedom.

10、A.

B.

C.

D.

正确答案：

1、Given the following information:Standard deviation = 8 Coefficient of variation = 64%The mean would then be

A.12.5

B. 8

C.0.64

D.1.25

正确答案：12.5

2、From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately