The number of boxes will weigh 18 ounces or less will be 138. Then the correct option is A.
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 z-score is given as
z = (x - μ) / σ
Where μ is the mean, σ is the standard deviation, and x is the sample.
The weights of boxes of rice produced at a factory are normally distributed with a mean of 20 ounces and a standard deviation of 1.5 ounces.
Consider a shipment of 1500 boxes of rice.
Then the number of the boxes will weigh 18 ounces or less will be
z = (18 - 20) / 1.5
z = -1.33
Then the probability will be
P(x ≤ 18) = P(z ≤ -1.33)
P(x ≤ 18) = 1 - P(z > -1.33)
P(x ≤ 18) = 1 - [1 - P(z < -1.33)]
P(x ≤ 18) = P(z < -1.33)
P(x ≤ 18) = 0.091211
Then the number of the boxes will weigh 18 ounces or less will be
⇒ 0.091211 x 1500
⇒ 136.8
approximately 138 boxes.
Then the correct option is A.
More about the normal distribution link is given below.
https://brainly.com/question/12421652
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