Question

A vending machine company wants to check three of its machines to determine if they are properly dispensing 12 ounces of coffee. Their data is given below α = 0.01.
Row Machine A Machine B Machine C
1 11.5 10.3 11.1
2 12.1 9.7 11.3
3 11.6 10.4 11.9
4 12.0 10.7 11.5
5 11.1 9.9 11.7
6 12.2 10.1 11.3
H0: μA = μB = μC
Ha: Not all means are equal
One-way ANOVA: Machine A, Machine B, Machine C
Source DF SS MS F P
Factor 2 8.363 4.182 31.73 0.000
Error 15 1.977 0.132
Total 17 10.340
P-value: _____
Decision: _____
Is there a significant difference between the vending machines A, B, and C? Use α=0.05.
A. No, there is no significant difference between the means.
B. Yes, there is a significant difference between the means.
C. The F-test cannot be used to answer whether or not there is a significant difference between the means.

Answer 1

Answer:

The correct option is B.

Step-by-step explanation:

The hypothesis to determine whether the vending machines are properly dispensing 12 ounces of coffee is:

H₀: $\mu_{A}=\mu_{B}=\mu_{C}$

Hₐ: Not all means are equal.

The ANOVA output is as follows:

One-way ANOVA: Machine A, Machine B, Machine C

Source           DF              SS                MS              F              P

Factor              2            8.363           4.182         31.73       0.000

Error               15             1.977            0.132

Total               17           10.340

The significance level is α = 0.05.

The p-value of the model is:

p-value = 0.000

Decision rule:

If the p-value of the test is less than the significance level then the null hypothesis will be rejected.

p-value = 0.000 < α = 0.05

The null hypothesis will be rejected.

Conclusion:

There is a significant difference between the means.

Thus, the correct option is B.