Name MATH 1342
Lab 12 - Ch.10 - Hypothesis Testing
Critical Thinking, Communication Skills, Empirical/Quantitative Skills
2. A machine is designed to fill jars with 16 ounces of coffee. A quality control inspector
suspects that the machine is not filling the jar with the full 16 ounces. A sample of 20 jars has
a mean of 15.8 ounces and a standard deviation of 0.32 ounce. Is there enough evidence to
support the inspector's claim that the mean number of ounces of coffee in the jars is less than
16? Use a = .05.
1.
Hand H
2.
3.
Critical value(s)
4.
Graph
5.
Test Statistic
6.
P-value
7.
Reject H. or Do Not Reject H.
8.
Conclusion

1 & 2:The null and alternate hypotheses are

H0 : u = 16 vs Ha: u < 16

The null hypothesis is that the mean is 16 ounces against the claim that it is less than 16 ounces.

3:The significance level is 0.05

4. Critical Value:

The critical region for significance level = 0.05  for one tailed test is z< ± 1.645

5.The test statistic

The test statistic to be used is

z= x- μ/σ/√n

z= 15.8-16/0.32/√20

z= -0.2/ 0.071556

z= -2.7950

6. The p-value ≈ 0.00259 for one tailed test.

7. Reject H0

Since the calculated value of z= -2.7950 is less than z∝= -1.645  we reject the null hypothesis.

8. Conclusion:

There is enough evidence to  support the inspector's claim that the mean number of ounces of coffee in the jars.

Graph

144.50

step-by-step explanation:

21.5 x 13.4=288.10 divide by 2