Use technology or a z-score table to answer the question.
The weights of logs in a wood pile are normally distributed with a mean of 17 pounds and a standard deviation of 3.4 pounds. The wood pile is composed of 325 logs.
How many of the logs will weigh 15 pounds or more?
I tried using the z-score formula 325-17
— =90.588 , this is not a possible answer since 90 is not on the z score table. Can you help me?
Mmmm....you got it a little messed up....we want to find the % that matches this computed z score
[ 15 - 17 ] / 3.4 = -.59
Look at the z score table for -.59 and you have ≈ .2776
So.....the number of logs weighing more than 15 lbs. is
[ 1 - .2776 ] (325) =
about 235 logs