Samples of aluminum-alloy channels were tested for stiffness. the following frequency distribution was obtained. The distribution is assumed to be normal. stiffness frequency2480 232440 352400 402360 332320 21a) What is the approximate mean of the population from which the sample were taken?b) What is the approximate standard deviation of the population from which the samples were taken?c) What is the approximate probability that stiffness would be less than 2350 for any given channel section?

The answer is explained below

Step-by-step explanation:

stiffness        frequency

2480             23

2440             35

2400             40

2360             33

2320             21

a) The mean for the population is calculated using the formula:

b) The standard deviation is given by:

c) We have to find the z score for x = 2350. The z score is given by:

From the z table:

The probability that stiffness would be less than 2350 for any given channel section = P(x < 2350) = P(z < -1.02) = 0.1539 = 15.39%

relating to or denoting a system of numbers and arithmetic based on the number ten, tenth parts, and powers of ten.

it alot will look like this 4.4

22.83 repeating

step-by-step explanation:

137 ÷ 6 is 22.8333333 therefore we understand that 3 is repeating.

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