The weights that represent 90% of the weight of a four years old boy will be 44.58
What is a z-score?
The z-score is a statistical evaluation of a value's correlation to the mean of a collection of values, expressed in terms of standard deviation.
The weights of four years old boys are normally distributed with a mean of 38 pounds and a standard deviation of 4 pounds.
The value of the z-score at 90% will be 1.645
Then the weights that represent the 90% of the weight of a four year old will be
1.645 = (x - 38)/4
6.58 = x - 38
x = 44.58
More about the normal distribution link is given below.
https://brainly.com/question/15016913
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