SOLUTION: Suppose the weights of 11000 male students are normally distributed with mean 160 ponds and Variance of 40 ponds. Find the number of students with weights. i- Less than 100 pound

Algebra.Com
Question 1105972: Suppose the weights of 11000 male students are normally distributed with mean 160 ponds and Variance of 40 ponds. Find the number of students with weights.
i- Less than 100 pounds
ii- Between 150 and 175 pounds
iii- Greater than 155 pounds
iv- Between 170 and 175 pounds
v- Greater than 210 pounds

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
SD is sqrt (40) or 6.32 pounds (the variance should be 40 pounds^2, since it is a quadratic term.)
les than 100 is essentially 0 since it is 60/6.32 sd s from the mean.
Between 150 and 175, z=(x-mean)/sd or (150-160)/6.32=-1.58 and (175-160)/6.32=+2.37. Probability of z between those is 0.9341
-----------
greater than 155 is z > (155-160)/6.32>=-0.7911, probability is 0.7856
----------
between 170 and 175 is z between (170-160/6.32=1.58 and 15/6.32=2.37, probability is 0.0482.
---------
greater than 210 is a z > 50/6.32 or essentially 0.

RELATED QUESTIONS

Suppose the weights of 2000 male students are normally distributed with mean =... (answered by ewatrrr)
if the height(X) of the college students are normally distributed with mean 69 and... (answered by VFBundy)
If the height of college students are normally distributed with mean 69 and variance 9,... (answered by Boreal)
Please help me to solve this problem. Q:At a certain large university, the weight of... (answered by Boreal)
10. The mean weight of 500 male students at a certain college is 151 pounds (lb), and the (answered by Fombitz)
Airlines have to estimate the weights of passengers. Assume that men have weights that... (answered by stanbon)
The Mean weight of 500 male students at VIT University is 151 lb and the standard... (answered by Boreal)
The heights of the male students at Wild West College are normally distributed with a... (answered by Boreal)
Suppose that the weight X of individual male patients registered at a certain diet clinic (answered by Boreal)