In a recent study, volunteers who had 8 hours of sleep were three times more likely to answer questions correctly on a math test than were sleep-deprived participants. 

Step-by-step explanation:

Sleep Deprivation

In a recent study, volunteers who had 8 hours of sleep were three times more likely to answer correctly on a math test than were sleep-deprived participants.

(a) Identify the sample used in the study.

(b) What is the sample's population?

(c) Which part of the study represents the descriptive branch of statitics?

(d) Make an inference based on the results of the study?

Solution

A. The samples used is the hours of sleep and math test scores of the volunteers

B. The samples population is hours of sleep and math test scores of people in general

C. The part of the study that represent the descriptive branch of statistics is "three times more likely"

D.Inference: To perform well in a math test, a person should get at least 8 hours of sleep the night before.

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5