SOLUTION: Question No. 7
A study conducted among 29-year-old male, acetone levels were normally distributed with a mean of 1070 and a standard deviation of 311 ppb. Find the probability tha
Algebra ->
Probability-and-statistics
-> SOLUTION: Question No. 7
A study conducted among 29-year-old male, acetone levels were normally distributed with a mean of 1070 and a standard deviation of 311 ppb. Find the probability tha
Log On
Question 1134222: Question No. 7
A study conducted among 29-year-old male, acetone levels were normally distributed with a mean of 1070 and a standard deviation of 311 ppb. Find the probability that on a given day the subject’s acetone level is:
a. Between 700 and 1100 ppb
b. Over 1000 ppb
c. Under 600 ppb
d. Between 1000 and 1200 ppb
Question No. 8
The weights of a certain population of young adult females are approximately normally distributed with a mean of 231 pounds and a standard deviation of 21. Find the probability that a subject selected at random from this population will weigh:
a. More than 175 pounds
b. 121 pounds or less
c. Between 115 and 155 pounds
You can put this solution on YOUR website! z=(x-mean)/sd
z is between -370/311 or -1.19 and 30/311, or 0.10 and probability is 0.4228
over 1000 has z of -70/311 or -0.225 and probability is 0.5890
under 600 has z of -470/311 or -1.51 and probability of 0.0655
between 1000 and 1200 has z of -0.225 and 130/311 or +0.42 and probability of 0.2518
same approach
z>(175-231)/21 or z>-2.67 probability of 0.9962
121 or fewer is probability of 0 by inspection. It is more than 5 sd s below the mean.
between 115 and 155 is essentially fewer than 155 or z <- 76/21 (-3.62) probability is 0.00015
