A large representative random sample of 6906 U. S. adults collected over 20 years showed that "parents reported higher levels of life satisfaction than nonparents," with the observed difference in life satisfaction between the two groups being statistically significant. This is an example of:
A) a matched pairs experiment
B) an observational study
C) a randomized comparative experiment

B- An Observational Study

Step-by-step explanation:

An Observational Study is a type of study in which individuals are observed for certain outcomes.

It helps researchers know what happens in real life situations. These studies serve as a collection of data from standard practice.

Also it is useful in studying rare events where one can retrospectively collect data to determine probable causes of problem and probable solutions.

it will be a cylinder. with a diameter of 8 and 4 single pieces high

step-by-step explanation:

answer: 94

step-by-step explanation: 79+91+92+94+94 = 450 divided by 5 (since there are 5 number that are being added) = 90