Quiz 2

Question 1

A numerical measure of linear association between two variables is the

a. variance
b. covariance
c. standard deviation
d. coefficient of variation

Answer 1

Covariance

Question 2

During a cold winter, the temperature stayed below zero for 10 days (ranging from -20 to -5). The variance of the temperatures of the ten day period

a. is negative since all numbers are negative
b. must be at least zero
c. can not be computed since all numbers are negative
d. can be either negative or postitive

Answer 2

Must be at least zero

Question 3

Excels _______ function can be used to compute the mean

a. MEDIAN
b. MODE
c. MAX
d. AVERAGE

Answer 3

AVERAGE

Question 4

Excels _____ function can be used to compute the population standard deviation

a. MODE
b. None of the other answers are correct
c. MAX
D. STDEV

Answer 4

Answer: None of the answers are correct

Question 5

Excels _____ function can be used to compute the sample covariance

a. CORREL
b. COVARIANCE/S
c. VAR
d. MAX

Answer 5

COVARIANCE.S

Question 6

Excels ______ function can be used the sample variance

a. STDEV
b. MAX
c. MODE
d. VAR.S

Answer 6

VAR.S

Question 7

Positive values of covariance indicate

a. a postive variance of the y values
b. the standard deviation is postive
c. a postitive relation betweent the x and y varibles
d. a positive variance of the x values

Answer 7

A positive relation between the x and the y variables

Question 8

The interquartile range is the difference between the

a. second and fourth quartiles
b. first and second quartiles
c. first and third quartiles
d. second and third quartiles

Answer 8

First and third quartiles

Question 9

The measure of location that is the most likely to be influences by the extreme values in the data set is the

a. range
b. mode
c. mean
d. median

Answer 9

Mean

Question 10

The most frequently occuring value of the data set is called the

a. mean
b. none of the answers are correct
c. mode
d. range

Answer 10

Mode

Question 11

The numerical value of the standard deviation can never be

a. zero
b. larger than the variance
c. negative
d. all of these statements are correct

Answer 11

Negative

Question 12

The variance of a sample of 81 observations equals 64. The standard deviation of the sample equals

a. 8
b. 4096
c. 0
d. 6,561

Answer 12

8

Question 13

The variance of the sample

a. can never be negative
b. can never be zero
c. cannot be less than one
d. can be negative

Answer 13

Can never be zero

Question 14

When the data are positively skewed, the mean will usually be

a. less than the mode
b. greater than the mode
c. less than the median
d. greater than the median

Answer 14

Greater than the median

Question 15

Which of the following is not a measure of dispersion?

a. the interquartile range
b. the standard deviation
c. the range
d. the 50th percentile

Answer 15

The 50th percentile

Question 16

Which odf the following is not a measure of variability of a single variable

a. range
b. coefficient of variation
c. standard deviation
d. covariance

Answer 16

Covariance

Question 17

Which of the following symbols represents the mean of the population?

a. u (mew)
b. o (variance)
c. (blank?)
d. o^2 (standard deviation)

Answer 17

Mew (u)

Question 18

Which of the following symbols represents the mean of the sample?

a. o
b (blank?)
c. u
d. o^2

Answer 18

(Blank??)

Question 19

Which of the following symbols represents the size of the population?

a. u
b. o
c. o^2
d. N

Answer 19

N

Question 20

Which of the following symbols represents the variance of the population?

a. o^2
b.o
c. u
d. (blank?)

Answer 20

o^2