Ateacher has given a test to a group of students. the set of scores is: 78, 79, 79, 81, and 83. find the variance for this group of tests.

a. 2.24

b. 3.4

c. 5

d. 80

can someone also explain to me how you got the answer so i can understand it.

The variance is 3.2

Step-by-step explanation:

step 1

Find the mean

[78+79+79+81+83]/5> 400/5> 80

step 2

 for each number: subtract the Mean and square the result

(78-80)²>4

(79-80)²> 1

(79-80)²> 1

(81-80)²> 1

(83-80)²> 9

step 3

 work out the mean of those squared differences

[4+1+1+1+9]/5> 16/5> 3.2> this value is called the "Variance"

part d

step-by-step explanation:

theresa talked her parents into getting sd cards for her phone and her brother’s phone. inserting an sd card into a phone gives it more storage. they both get 8-gigabyte sd cards. how many bits of storage come with each sd card? type your answer in both scientific and standard notation.