The given expressions are :
The mean is 250.875.
Using this information, I can put the following into a calculator:
√(((250.875-195)²+(250.875-358)²+(250.875-201)²+(250.875-276)²+
(250.875-161)²+(250.875-301)²+(250.875-387)²+(250.875-128)²)÷8)
Which equals:
87.9878
This is the standard deviation of the MP3 players.
Answer:
The simplified form of the expression is
.
Step-by-step explanation:
The expression is:

The division rule of exponents is:

The negative exponent rule is:

Simplify the expression as follows:
![\frac{x^{-3}\cdot y^{2}}{x^{4}\cdot y^{6}}=[x^{-3-4}]\times [y^{2-6}]](https://tex.z-dn.net/?f=%5Cfrac%7Bx%5E%7B-3%7D%5Ccdot%20y%5E%7B2%7D%7D%7Bx%5E%7B4%7D%5Ccdot%20y%5E%7B6%7D%7D%3D%5Bx%5E%7B-3-4%7D%5D%5Ctimes%20%5By%5E%7B2-6%7D%5D)

Thus, the simplified form of the expression is
.
The series in the form of arithmetic progression
The notation of A.P is a, a+d, a+2d.....
The summation notation is â‘
In this series a=3, d=7
Then the summation of A.P is â‘ = n/2(2a+(n-1)d)
=18/2(2*3+ (18-1)7)
= 9(6+17(7))
=9(6+119)
=9(125)
= 1125
Hence the total number of beads is 1125