Question

The monthly revenue at a christian rock band has records to indicate that the mean monthly revenue is $2,400 and standard deviation is $600. A random sample of 81 months was selected. Find the approximate probability that the average revenue for the sample is less than $2,300.

Answer 1

Solution :

Given that ,

= $2400

= / n = 600 / 81 = 66.67

P( < 2.300) = P(( - ) / < (2300 - 2400) / 600)

= P(z < - 1.50)

Using z table

= 0.0668