Question

The average high temperatures in degrees for a city are listed.

58, 61, 71, 77, 91, 100, 105, 102, 95, 82, 66, 57

If a value of 98° is added to the data, how does the mean change?

A. The mean increases by 8.2°.
B. The mean decreases by 8.2°.
C. The mean increases by 1.4°.
D. The mean decreases by 1.4°.

Answer 1

The answer is c it increases by 1.4

Answer 2

C. The mean increases by 1.4°.

Explanation:

if you count the number of numbers in the set {58, 61, 71, 77, 91, 100, 105, 102, 95, 82, 66, 57} it is 12 numbers.

The formula for mean is,
`mean=(sum- of- the- terms)/(number-of-terms)`

so if you add all the numbers here →, {58, 61, 71, 77, 91, 100, 105, 102, 95, 82, 66, 57} you get a sum of 965.

Now 965 ➗12= 80.4166666667

If 98 is added we add 98 to 965 and get 1063.

That also means an additional number is being added so 12+1 = 13.

Now, 1063➗13= 81.7692307692

Ok now we approximate, 80.4166666667 is about 80.4 and 81.7692307692 is about 81.8.

Now we subtract 81.8-80.4 and get 1.4.

It was an increase of 1.4 in the mean so the answer is C.

SORRY IF MY EXPLAINING IS BAD ITS MY 1ST OR 2ND TIME EVER ANSWERING!! :)