SOLUTION: The average reading speed of fourth grade students is approximately normally distributed with a mean of 140 words per minute (wpm) and a standard deviation of 22 wpm. The probab

Algebra ->  Probability-and-statistics -> SOLUTION: The average reading speed of fourth grade students is approximately normally distributed with a mean of 140 words per minute (wpm) and a standard deviation of 22 wpm. The probab      Log On


   

Question 1197759: The average reading speed of fourth grade students is approximately normally distributed with a mean of 140 words per minute (wpm) and a standard deviation of 22 wpm.
The probability that the mean reading speed for a group of 32 fourth graders exceeds _________ is 10%. Give the value that fills in the blank, and include two digits after the decimal.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi  
Normal Distribution: µ = 140,  and σ = 22 wpm
The probability that the mean reading speed for a group of 32 fourth graders exceeds _________ is 10%.

Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus
z = Invnorm(.90) = 9.5026
 x = 22*9.5026 + 140 = 357.61wpm
Wish You the Best in your Studies.