Adimas found the mean of her 11 math test scores for the first semester. x = ≈ 81 using 81 as the mean, find the variance of her grades rounded to the nearest hundredth. σ2 = find the standard deviation of her grades rounded to the nearest hundredth. σ =

The complete question is attached.

To find the variance and deviation, we have to use their definition or formulas:

So, first we have to find the difference between each number and the mean:

76-81=-5

87-81=6

65-81=-16

88-81=7

67-81=-14

84-81=3

77-81=-4

82-81=1

91-81=10

85-81=4

90-81=9

Now, we have to elevate each difference to the squared power and then sum all:

Then, we replace in the formula:

The variance is just the squared power of the standard deviation. So:

rx and sx

step-by-step explanation:

answer: i think one of the answer is $150 and $300?

step-by-step explanation: