In: Math
A large tank of fish from a hatchery is being delivered to a
lake. The hatchery claims that the mean length of fish in the tank
is 15 inches, and the standard deviation is 4 inches. A random
sample of 28 fish is taken from the tank. Let x be the
mean sample length of these fish. What is the probability that
x is within 0.5 inch of the claimed population mean?
(Round your answer to four decimal places.)
Solution :
Given that,
mean = = 15
standard deviation = = 4
n = 28
=
= / n = 4 / 28 = 0.76
P(14.5< < 15.5 )
= P[(14.5 -15) / 0.76 < ( - ) / < (15.5 - 15) / 0.76 )]
= P(- 0.66 < Z < 0.66)
= P(Z < 0.66 ) - P(Z < - 0.66)
Using z table,
= 0.7454 - 0.2546
= 0.4908