Find the surface area. round your answer to the nearest tenth.​

a) mean =  11.1

b) Standard Deviation = 5.191

Step-by-step explanation:

Given the data in the question;

x = 5.2, 13.8, 8.6, and 16.8

sample n = 4

so;

            x            ( x - mean)²

          5.2             34.81

          13.8            7.29

          8.6             6.25

          16.8            32.49

∑        44.4            80.84

a) Mean

Mean = total sum of the sample divided by the sample size

mean = ∑x / n

we substitute

mean = 44.4 / 4

mean =  11.1

b)

Standard Deviation is the Square root of variance;

Variance = ∑(x-mean)² / n - 1

we substitute from the above table

Variance =  80.81 / 4 - 1

Variance =  80.81 / 3

Variance =  26.94667

now since Standard Deviation is the Square root of variance;

Standard Deviation = √Variance

Standard Deviation = √26.94667

Standard Deviation = 5.191