Question

1. find the mean, varience and standard deviation for the following data set
49,32,35,43,45,40,53,55,42

2.identify the inverse of the following function
h(x)= 1 + 1/2x

Answer 1

For the mean, add them up , then divide by 9

To find the variance:

- take the difference between each data value and the mean, (some will be
positive, others negative, doesn't matter)
- square these difference, (now they are all positive)
- add up all those squared differences
- divide by either n or n-1, where n is the number of data values, yours: n=9

(check with your text or your course notes which approach you are
supposed to take in dividing by either 9 or 8

for the standard deviation, take the square root of the variance.


the inverse of the following function
h(x)= 1 + 1/2x
I will assume you meant: h(x) = 1 + 2/(2x)

let y = 1 = 1/(2x)
step1: interchange the x and y variables....
x = 1 + 1/(2y)

step2: solve this new equation for y
multiply both sides by 2y
2xy = 2y + 1
2xy - 2y = 1
y(2x - 2) = 1
y = 1/(2x - 2) <------- your inverse