Statistics from Cornell's Northeast Regional Climate Center indicate that Ithaca, NY, gets an average of 35.4 inches of rain eac
h year, with a standard deviation of 4.2 inches. During what percentage of years does Ithaca get more than 30 inches of rain?
a. approximately 10.03%
b. approximately 10.95%
c. approximately 90.07%
d. approximately 5.82
e. approximately 94.18%
We need to calculate z-statistic of 30 inches of rain in the normal distribution with an average of 35.4 inches of rain each year, and a standard deviation of 4.2 inches.
z score can be calculated using the formula
z= where
X =30 inches of rain
M is the average rain in inches (35.4)
s is the standard deviation (4.2)
using the numbers we get z= ≈ −1,286
Then percentage of years does Ithaca get more than 30 inches of rain is
P(z>-1.286) =1- P(z<-1.286)=1-0.0993 ≈0.9007 or 90.7%
Both together cost $1759. That means that sum of the two prices is $1759. The operation that is the opposite of addition is subtraction. We subtract $469 from $1759 to find the price of the televition.