biostats
posted by maria .
what is the probability by Pr( X ≥ 8) years where X is normally distributed with mean 5.24 and sd = 1.90?
HELP!!!
thank you!

biostats 
maria
complete this:
We estimate the probability by Pr( X ≥ 8) years where X is normally distributed with mean 5.24 and sd = 1.90.
Assuming normal distribution we want prob that x >=8
P(x>=8) = P(Z >= (8  5.24)/1.90) = P(Z >= 1.45) = 1  P(Z<1.45) = 
biostats 
Scott
use a zscore table to find the portion of the population below 1.45 sd above the mean
looks like about .93
so prob X ≥ 8 is ... 1  .93
Respond to this Question
Similar Questions

college
Assume that the life expectancy of U.S. males is normally distributed with a mean of 80 years and a standard deviation of 4 years. What is the probability that a randomly selected male will live more than 85 years? 
Statistics
The average age of chemical engineers is 37 years with a standard deviation of 4 years. If an engineering firm employs 25 chemical engineers, find the probability that the average age of the group is greater than 38.2 years old. If … 
statistics
At a large publishing company, the mean age of proofreaders is 36.2 years, and the standard deviation is 3.7 years. If a random sample of 15 proofreaders is selected, find the probability that the mean age of the proofreaders in the … 
probability
1. The time it takes a student to cycle to school is normally distributed with a mean of 15 minutes and a variance of 2. The student has to be at school at 8.00a.m. At what time should the student leave her house so that she will be … 
statistik
can you show me the calculation ;) The life expectancy of computer terminals is normally distributed with a mean of 4 years and standard deviation for 10 months. a. What is the probability that a randomly selected terminal will last … 
Biostats
What statistical methods a researcher can use to determine if weights of the children in pounds are normally distributed or not? 
statistics
5) The lifetime of a medical device s a normally distributed rv with standard deviation of 2 years. An experiment is conducted to test 15 medical devices and find their lifetimes to be: a. If the population mean is known to be 15 years, … 
Quantitative Analysis for Business
The ages of a group of 50 women are approximately normally distributed with a mean of 48 years and a standard deviation of 5 years. One women is randomly selected from the group, and her age is observed. A) Find the probability that … 
Statistics
In a certain population the heights of men are normally distributed with mean 168.75 and variance 42.25 those of women are normally distributed with mean 162.50 and variance 36 the probability that the mean height of a random sample … 
statistic
A manufacturer knows that their items have a normally distributed lifespan, with a mean of 11.9 years, and standard deviation of 2.2 years. If you randomly purchase one item, what is the probability it will last longer than 18 years?