Answer:
Explanation:
Let x be the random variable representing the the length of newborn babies (in inches). Since it is normally distributed and the population mean and population standard deviation are known, we would apply the formula,
z = (x - µ)/σ
Where
x = sample mean
µ = population mean
σ = standard deviation
From the information given,
µ = 20 inches
σ = 2.6 inches
the probability that a given infant is between 14.8 and 25.2 inches long is expressed as
P(14.8 ≤ x ≤ 25.2)
For x = 14.8,
z = (14.8 - 20)/2.6 = - 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.023
For x = 25.2
z = (25.2 - 20)/2.6 = 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.98
Therefore,
P(14.8 ≤ x ≤ 25.2) = 0.98 - 0.23 = 0.75