Standard Normal Distribution

For Question #1 (about the telephone company), what is the z score associated with 255? (rounded to 2 decimals).

For Question #1 (about the telephone company), what is the z score associated with 230 second phone call?

For Question #1 (about the telephone company), what is the area under the normal curve between 230 and 255 seconds? Write the answer as a decimal (rounded to 3 decimals).

For Question #1b (about the telephone company), what is the probability the length of a call is greater than 255 seconds? (rounded to 3 decimals).

For Question #2a) (IQ question), what percent of the patients have intelligence quotients less than 89? (just input numbers, and round to the whole percent).

For Question #2b) (IQ question), what percent of the patients have intelligence quotients between 89 and 120? (just input numbers, and round to the nearest percent).

For Question #2c) (IQ question), what percent of the patients have intelligence quotients between 110 and 120? (just input numbers, and round to the nearest percent).

For Question #2d) (IQ question), what percent of the patients have intelligence quotients greater than 120? (just input numbers, and round to the nearest percent).

Refer to Question #1a) What is the probability notation to denote the area between 230 and 255 seconds? Choose all that apply.

• P(230 < X < 255)

• P( 230 < z < 255)

• P( 0 < z < 0.42)

• P ( 0.42 < X < 0)

Refer to Question #1a) What is the probability notation to denote the area greater than 255 seconds? Choose all that apply.

• P(255 < X )

• P( 255 < z )

• P( 0.42 < z)

• P ( X >255)