A piano teacher charges $30 for a one hour lesson, and $50 for a two hour lesson. She works for 25 hours in one week, and earns

Response:

24.2 (rounded to the nearest tenth)

Detailed breakdown:

The data type involved is ungrouped

standard deviation =√ [∑ (x-μ)² / n]

average (μ)=∑x/n

           =

          =33.3

For the values 5, 5, 6, 12, 13, 26, 37, 49, 51, 56, 56, 84, the x-μ results will be

                   -28.3, -28.3, -27.3, -21.3, -7.3, 3.7, 15.7,17.7, 22.7,22.7,50.7

Calculating (x-μ)² gives: 800.89, 800.89, 745.29, 453.69, 53.29, 13.69, 246.49, 313.29, 515.29, 515.29, 2570.49

Then, ∑ (x-μ)² results in = 7028.59

Thus, standard deviation = √(7028.59 / 12)

                      =24.2

Solution:

x=8

Detailed explanation:

This isosceles triangle consists of two right triangles with sides equal to 8,, and y

Considering we possess two sides of a right triangle, determining the third side can be achieved using the Pythagorean Theorem

Because it is an isosceles triangle, these two right triangles are the same, thus x=2y

Hence, x=2(4)=8