In: Math
The mean number of pets per household is 2.96 with standard deviation 1.4. A sample of 52 households is drawn. Find the probability that the sample mean is less than 3.11.
a. |
0.2245 |
|
b. |
0.5676 |
|
c. 0.3254 |
||
d. |
0.7726 |
Solution :
Given that ,
mean = = 2.96
standard deviation = = 1.4
n = 52
= 2.96 and
= / n = 1.4 / 52 = 0.1941
P( < 3.11) = P(( - ) / < (3.11 - 2.96) / 0.1941)
= P(z < 0.7474)
Using standard normal table,
P( < 3.11) = 0.7726
Probability = 0.7726
Option d)