Find the standard deviation if the mean of a sample is 72, a z-score of 3 Raw Score: 42 Raw Score: 81

a) when x = Raw Score: 42

Standard deviation = σ = -10.3

b) Raw Score: 81

Standard deviation = σ = 2.67

Step-by-step explanation:

Find the standard deviation if the mean of a sample is 72, a z-score of 3

Z score formula is given :

z = (x-μ)/σ,

where

x is the raw score

μ is the population mean = 73

σ is the population standard deviation

z = 3

a) when x = Raw Score: 42

z = (x-μ)/σ

3 = 42 - 73/σ

Cross Multiply

3σ = 42 - 73

3σ = -31

σ = -31/3

σ = -10.3

b) Raw Score: 81

z = (x-μ)/σ

3 = 81 - 73/σ

Cross Multiply

3σ = 81 - 73

3σ = 8

σ = 8/3

σ = 2.67

part 1 answer = 8

part 2 answer = 72

step-by-step explanation:

part 1 explanation = add all of the numbers, then divide by how many numbers you have. so, 200/25 = 8.

part 2 explanation = not gonna lie, this is hard to explain, so just google how to do it.

y = 2x

step-by-step explanation:

if you divide each number in the sequence, you'll see that they all have a multiple factor of 2. each number in the series, and any other numbers which may continue, will be multiplied by 2. therefore, y is the next number in the sequence, and x is the current one, so, our formula will be y = 2x.