Your school has a new restaurant in the food court. Every day it has a different meal and different price. A friend told you that the average price is $10. You wanted to test if your friend is correct. You collected a sample of 20 lunch for 20 days. The mean price your paid for lunch is $11.5 with a standard deviation of $2.2. Assume that the price is normally distributed.
Test the hypothesis that the mean price for lunch is different from $10. What is your conclusion?
Solution :
This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 10
Ha : 10
= 11.5
= 10
= 2.2
n = 20
df = 20 - 1 = 19
Test statistic = t
= ( - ) / s / n
= (11.5 - 10) / 2.2 / 20
= 3.05
Test statistic = 3.05
P-value = 0.0066
= 0.05
P-value <
Reject the null hypothesis .
There is enough evidence to suggest that the mean price for lunch is different from $10 .
Get Answers For Free
Most questions answered within 1 hours.