Practice Free Response 4
The mean height of the seat of a standard high school student chair attached to a desk is 18 inches with a
standard deviation of 0.6 inches. The heights of all high school student chairs
attached to a desk can be
reasonably approximated by a normal distribution.
(a) What proportion of high school student chairs attached to a desk have a height that is greater than 19
normcdf (lower
inches?
Z-Score: 19-18
96
limit
= 1.67
Upper
Limit,
mean, s.D)
A random sample of 5 chairs is to be chosen.
(b) What is the probability that exactly 2 of the chairs have a height greater than 19 inches?
sample
binom pdf size, Probability, # of successes)
(s
(c) What is the probability that the sample mean of the 5 chairs is greater than 19 inches?
normcdf
5.D.
√n
SE=0.60.268
√5
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