Answer:
There is a 2.28% chance that more than 250 books were borrowed in a week.
Thus the probability that more than 250 books were borrowed in a week is 0.0228 = 2.28%
Step-by-step explanation:
d) the probability that, on average, the number of books borrowed from the library as a mean of 190 and standard deviation of 30.
The area under part of a normal probability curve is directly proportional to probability and the value is calculated as
z = (x₁−x) /σ
where z = propability of normal curve
x₁ = variate mean = 250
x = mean of 190
σ = standard deviation = 30
applying the formula,
z= (250-190)/30
z = 60/30 =2
Using a table of partial areas beneath the standardized normal curve (see Table of normal curve, a z-value of 2 corresponds to an area of 0.4772 between the mean value. but, because the standard curve has 0.5, then will minus 0.4772 from 0.5= 0.5 - 0.4772 = 0.0228
Thus the probability that more than 250 books were borrowed in a week is 0.0228 = 2.28%
