The National Sporting Goods Association (NSGA) conducted a survey of the ages of individuals that purchased skateboarding footwear. The ages of this survey are summarized in the following relative frequency distribution. Suppose the survey was based on a sample of 200 individuals. Age of User Percent Under 14 years old 35 14 to 17 years old 41 18 to 24 years old 15 25 to 34 years old 4 35 to 44 years old 4 45 to 64 years old 1 Calculate the mean, variance and standard deviation of the age of individuals that purchased skateboarding shoes. Use 10 as the midpoint of the first class. (Round your answers to 2 decimal places.)

μ = 16.31

σ² = 11.22

σ = 3.35

Step-by-step explanation:

The mean is the sum of the midpoints times the percentage.

μ = ∑ (mx)

The variance is the sum of the squared differences between the midpoints and the mean, all divided by the total number of people minus one.

σ² = ∑ (m − μ)² / (n − 1)

And the standard deviation is the square root of the variance.

First, we calculate the mean.

Now, we find the variance.

The standard deviation is therefore σ = 3.35.

it is contrapositive

i could not see the question too well so check yourself again too . this is because i want you to get it correct.

answer: what in the world is this

step-by-step explanation: