Question

In a study conducted by biologists Sokal and Hunter, the wing lengths of houseflies were found to be approximately normally distributed, with a mean wing length of 45.5 mm, and a standard deviation of 3.92 mm.

A housefly is randomly selected, find the probability that its wing length is less than 45 mm.  

Answer 1

Solution :

Given that,

mean = = 45.5

standard deviation = = 3.92

P(X<45 ) = P[(X- ) / < (45-45.5) / 3.92]

= P(z < -0.13)

Using z table

=0.4483