True or False Statements for the Midterm

Question 1

The population mean parameter is a constant, unknown in practice in general.

Answer 1

True

Question 2

The variance of a sample made of constant quantities (e.g., n = 3 and x1 = x2 = x3 = 10) is zero.

Answer 2

True

Question 3

The expected value of the sum of two random variables is always equal to the sum of the population means of the two random variables.

Answer 3

True

Question 4

In the general case, the population variance of the sum of two random variables is equal to the sum of the population variances of the two random variables plus an extra term.

Answer 4

True

Question 5

The expected value of the mean of an i.i.d. random sample is always equal to the population mean.

Answer 5

True

Question 6

Answer 6

False

Question 7

Answer 7

False

Question 8

Answer 8

True

Question 9

The median may exist for a sample of qualitative data.

Answer 9

True

Question 10

Answer 10

False

Question 11

Answer 11

False

Question 12

Answer 12

True

Question 13

Answer 13

True

Question 14

The expected value of the sum of two random variables is always equal to the sum of the population means of the two random variables.

Answer 14

True

Question 15

In the general case, the population variance of the sum of two random variables is equal to the sum of the population variances of the two random variables plus an extra term.

Answer 15

True

Question 16

The population mean of a normal distribution is also its population median and population mode.

Answer 16

True

Question 17

The median always exists for a sample of qualitative data.

Answer 17

False

Question 18

The expected value of a constant is the constant itself.

Answer 18

True

Question 19

The expected value of the sum of two random variables is always equal to the sum of the population means of the two random variables.

Answer 19

True

Question 20

The population variance of a constant is equal to the constant.

Answer 20

False

Question 21

The population mean of a normal distribution is also its population median and population mode.

Answer 21

True

Question 22

Answer 22

True

Question 23

Answer 23

True

Question 24

Answer 24

True

Question 25

The sample mean is random because its value changes from random sample to random sample.

Answer 25

True

Question 26

The variance of a random sample made of negative numbers is zero or positive.

Answer 26

True

Question 27

Answer 27

True

Question 28

Answer 28

True

Question 29

Answer 29

False

Question 30

Answer 30

False

Question 31

The median statistic never exists for a sample of qualitative data.

Answer 31

False

Question 32

Answer 32

False

Question 33

Answer 33

True

Question 34

Answer 34

True

Question 35

The median statistic exists sometimes but not always for qualitative sample data.

Answer 35

True

Question 36

Answer 36

False

Question 37

Answer 37

False

Question 38

Answer 38

True