Question

Average box of crackers is 24.5 ounces with standard deviation of. 8 ounce. What percent of the boxes weigh more than 22.9 ounces? What percent weigh less than 23.7 ounces?

Answer 1

Answer:

97.7% of of the boxes weigh more than 22.9 ounces.

15.9% of of the boxes weigh less than 23.7 ounces.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ =  24.5 ounces

Standard Deviation, σ = 0.8 ounce

We are given that the distribution of boxes weight is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(boxes weigh more than 22.9 ounces)

P(x > 22.9)

$P( x > 22.9) = P( z > \displaystyle\frac{22.9 - 24.5}{0.8}) = P(z > -2)$

$= 1 - P(z \leq -2)$

Calculation the value from standard normal z table, we have,  

$P(x > 22.9) = 1 - 0.023 =0.977= 97.7\%$

97.7% of of the boxes weigh more than 22.9 ounces.

b) P(boxes weigh less than 23.7 ounces)

P(x < 23.7)

$P( x < 23.7) = P( z < \displaystyle\frac{23.7 - 24.5}{0.8}) = P(z < -1)$

Calculation the value from standard normal z table, we have,  

$P(x < 23.7) =0.159= 15.9\%$

15.9% of of the boxes weigh less than 23.7 ounces.