Question

The reading speed of second grade students in a large city is approximately normal, with a mean of 90 words per

Answer 1

Answer:

The probability that a random sample of 10 second grade students from     the city results in a mean  reading rate of more than 96 words per minute

P(x⁻>96) =0.0359

Step-by-step explanation:

Explanation:-

Given sample size 'n' =10

mean of the Population = 90 words per minute

standard deviation of the Population =10 wpm

we will use formula

                           $Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }$

Let X⁻  = 96

                           $Z = \frac{96-90 }{\frac{10}{\sqrt{10} } }$

                          Z =  1.898

The probability that a random sample of 10 second grade students from     the city results in a mean  reading rate of more than 96 words per minute

$P(X^{-}>x^{-} ) = P(Z > z^{-} )$

                   = 1- P( Z ≤z⁻)

                   = 1- P(Z<1.898)

                   = 1-(0.5 +A(1.898)

                   = 0.5 - A(1.898)

                   = 0.5 -0.4641 (From Normal table)

                  = 0.0359

Final answer:-

The probability that a random sample of 10 second grade students from  

                = 0.0359