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The average weight of a human baby at birth is 7.3 pounds with a standard deviation of 2.6 pounds. What is the probability that a sample of 22 babies would have an average birth weight of 6.9 pounds or less?

Respuesta :

Rootsyl

Answer:

~0.2358

Explanation:

This is a normal distribution question:

Our formula is Z = (xbar-μ)/(σ/sqrt(n))

mü = 7.3

sigma = 2.6

sqrt(n) ~= 4.69

and wanted prob (xbar) <= 6.9

The formula gives us Z value of ~= -0.72

Then if we look at the z table we will find 0.2358