The governor of a state wanted to assess the public education system of the state. She instructed a group of researchers to create a test to assess the knowledge of every high school senior in the state. The researchers administered the tests and found that the average score was

78

78 points out of 100, with a standard deviation of

49

49 points. Complete parts (a) through (c) below.

a. Identify the population and variable.

Choose the correct population below.

A.

The population is the group of all high school teachers in the state.

B.

The population is the group of all high school seniors in the state.

C.

The population is the group of every state's governor.

D.

The population is the group of all high school students in the state.

Choose the correct variable below.

A.

The variable is the test length.

B.

The variable is the test score.

C.

The variable is the number of high school students.

D.

The variable is the number of high school seniors.

b. For samples of size

225

225, find the mean

mu Subscript x overbar

x and standard deviation

sigma Subscript x overbar

x of all possible sample mean test scores.

mu Subscript x overbar

x

equals

=

nothing

(Type an integer or a decimal.)

sigma Subscript x overbar

x

equals

=

nothing

(Round to one decimal place as needed.)

c. Repeat part (b) for samples of size

450

450.

mu Subscript x overbar

x

equals

=

nothing

(Type an integer or a decimal.)

sigma Subscript x overbar

x

equals

=

nothing

(Round to one decimal place as needed.)