Question

The reading speed of second grade students in a large city is approximately​ normal, with a mean of 9090 words per minute​ (wpm) and a standard deviation of 10 wpm. Complete parts​ (a) through​ (f). ​(a) What is the probability a randomly selected student in the city will read more than 9494 words per​ minute? The probability is nothing.

Answer 1

Answer: 0.3446

Explanation:

Given : Mean :
`\mu = 90`

Standard deviation :
`\sigma = 10`

Also, the reading speed of second grade students in a large city is approximately​ normal.

Then , the formula to calculate the z-score is given by :_

`z=(x-\mu)/(\sigma)`

For x = 94

`z=(94-90)/(10)=0.4`

The p-value =
`P(z>0.4)=1-P(z<0.4)=1-0.6554217`

`\\\\=0.3445783\approx0.3446`

Hence, the probability a randomly selected student in the city will read more than 94 words per​ minute =0.3446