Which of the following activities are examples of data gathering? check all that apply. a. surveying students about their favorite type of math problem b. making a spreadsheet from data found in a survey c. sampling water for contaminants d. making a pie chart about a group's favorite activities e. finding the mean weight of heart-disease patients in a study

A.  Surveying students about their favorite type of math problem; C.Sampling water for contaminants

Explanation:

Data gathering involves actually collecting data yourself instead of using data gathered beforehand by someone else.

In choice A, you are performing the survey yourself so you are gathering the data.

In choice B, you are using data found in a survey; this has been gathered by someone else, so you are not gathering the data.

In choice C, you are taking the sample yourself; this is gathering the data.

In choice D, you are making a chart using data already gathered; you are not gathering the data.

In choice E, you are finding the mean of data already gathered; this is not gathering the data yourself.

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: