The fitness center held a weight loss competition in which 128 people participated. The amount of weight loss was normally distributed with a mean of 18 pounds and a standard deviation of 5.4 pounds. Approximately how many people lost at least 15 pounds?

37

Step-by-step explanation:

Given :

Sample size, n = 128

Mean, μ = 18

Standard deviation, σ = 5.4

Number of people who lost atleast 15 pounds :

The Zscore = (x - μ) / (σ)

Zscore = (15 - 18) / 5.4

Zscore = - 3 / 5.4

Zscore = - 0.5555

P(Z < - 0.555) = 0.28945

Number of people who lost atleast 15 pounds :

0.28945 * 128 = 37.0496

= 37 people

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: