A few days ago
Anonymous

Make up frequency distributions of four scores between 10 & 100 that have the given mean and std. deviation???

A) M=80, sigma < 3 B) M=80, sigma > 20

C) M=80, sigma = 10

Please help, be clear and detailed, thanks in advance

Top 1 Answers
A few days ago
Merlyn

Favorite Answer

A)

{78, 79, 81, 82}

mean = 80

standard deviation = 1.825742

B)

{60,61,99,100}

mean = 80

std dev = 22.52406

C)

variance = (std dev)^2

variance = 1/3 * [(x-80)^2 + (y-80)^2 + (z-80)^2 + (w-80)^2]

100 = 1/3 * [(x-80)^2 + (y-80)^2 + (z-80)^2 + (w-80)^2]

300 = [(x-80)^2 + (y-80)^2 + (z-80)^2 + (w-80)^2]

300 = x² + y² + z² + w² – 160 * (x + y + z + w) + 25600

300 = x² + y² + z² + w² – 160 * (120) + 25600

300 = x² + y² + z² + w² – 25600

25900 = x² + y² + z² + w²

work this out, i’d do some more with it right now but I’m at work and should get back to that.

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