SOLUTION: Given belly button height (x) of students is normally distributed with a mean of 100cm and a standard deviation of 20cm. Find P(90 < x < 120). Given that X the random variable bel

Algebra ->  Probability-and-statistics -> SOLUTION: Given belly button height (x) of students is normally distributed with a mean of 100cm and a standard deviation of 20cm. Find P(90 < x < 120). Given that X the random variable bel      Log On


   

Question 610069: Given belly button height (x) of students is normally distributed with a mean of 100cm and a standard deviation of 20cm. Find P(90 < x < 120).
Given that X the random variable belly button height (x) has a mean of 100 cm and standard deveiation of 20cm. Find belly button height x, such that P(belly button height [X] <=x) = 0.025.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Given belly button height (x) of students is normally distributed with a mean of 100cm and a standard deviation of 20cm. Find P(90 < x < 120).
----
z(90) = (90-100)/20 = -10/20 = -1/2
z(120) = (120-100)/20 = 1
P(90 < x < 120) = P(-1/2 < z < 1) = 0.7263
=================
Given that X the random variable belly button height (x) has a mean of 100 cm and standard deveiation of 20cm. Find belly button height x, such that
P(belly button height [X] <=x) = 0.025.
-----------------------------------------
Find the z-value with a left tail of 0.025
z = invNorm(0.025) = -1.96
---
Find "x" using x = zu + u
x = -1.96*20 + 100
x = 60.8 in
==================
Cheers,
Stan H.
==================