In: Statistics and Probability
Masterfoods USA states that their color blends were selected by conducting consumer preference tests, which indicated the assortment of colors that pleased the greatest number of people and created the most attractive overall effect. On average, they claim the following percentages of colors for M&Ms® milk chocolate candies: 24% blue, 20% orange, 16% green, 14% yellow, 13% red and 13% brown.
Question: On average, they claim that a 1.69 oz bag will contain more than 54 candies. Test this claim (µ > 54) at the 0.01 significance (σ unknown).
Blue | Orange | Green | Yellow | Red | Brown | Total Number of Candies in Bag |
6 | 17 | 10 | 8 | 10 | 7 | 58 |
8 | 8 | 11 | 12 | 9 | 10 | 58 |
8 | 13 | 14 | 4 | 12 | 7 | 58 |
7 | 13 | 10 | 7 | 14 | 7 | 58 |
12 | 13 | 4 | 13 | 5 | 10 | 57 |
13 | 8 | 12 | 13 | 1 | 10 | 57 |
8 | 8 | 14 | 7 | 9 | 11 | 57 |
16 | 10 | 10 | 5 | 11 | 4 | 56 |
11 | 11 | 8 | 13 | 6 | 7 | 56 |
10 | 9 | 14 | 10 | 9 | 4 | 56 |
6 | 12 | 13 | 8 | 9 | 8 | 56 |
14 | 10 | 2 | 13 | 7 | 10 | 56 |
11 | 10 | 11 | 12 | 5 | 7 | 56 |
14 | 11 | 8 | 6 | 7 | 10 | 56 |
14 | 8 | 9 | 5 | 5 | 15 | 56 |
11 | 12 | 10 | 12 | 7 | 3 | 55 |
12 | 9 | 12 | 8 | 5 | 9 | 55 |
7 | 12 | 10 | 7 | 10 | 9 | 55 |
8 | 9 | 13 | 11 | 10 | 4 | 55 |
10 | 11 | 9 | 10 | 6 | 9 | 55 |
10 | 10 | 9 | 10 | 7 | 9 | 55 |
9 | 3 | 9 | 13 | 8 | 13 | 55 |
10 | 8 | 13 | 10 | 9 | 5 | 55 |
11 | 6 | 11 | 7 | 8 | 12 | 55 |
12 | 13 | 10 | 11 | 5 | 3 | 54 |
12 | 8 | 5 | 15 | 8 | 6 | 54 |
12 | 8 | 5 | 15 | 8 | 6 | 54 |
14 | 14 | 9 | 4 | 6 | 7 | 54 |
13 | 7 | 12 | 9 | 4 | 9 | 54 |
13 | 10 | 11 | 8 | 5 | 6 | 53 |
7 | 11 | 10 | 9 | 7 | 9 | 53 |
9 | 14 | 8 | 6 | 6 | 10 | 53 |
12 | 10 | 8 | 7 | 9 | 6 | 52 |
10 | 7 | 11 | 7 | 8 | 8 | 51 |
11 | 3 | 12 | 8 | 7 | 10 | 51 |
8 | 10 | 12 | 6 | 7 | 6 | 49 |
let X denotes the total number of candies in a bag.
: Mean total number of candies in a bag.
We have to test the hypothesis that
The bag will contain more than 54 candies or not.
i.e. Null Hypothesis -
against
Alternative Hypothesis- ( Right-tailed test).
Since population standard deviation (sigma) is unknown.
We used one sample t-test for testing population mean.
The value of test statistic is
X | ( X-Xbar)^2 |
58 | 9.3364 |
58 | 9.3364 |
58 | 9.3364 |
58 | 9.3364 |
57 | 4.2253 |
57 | 4.2253 |
57 | 4.2253 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
56 | 1.1142 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
55 | 0.0031 |
54 | 0.8920 |
54 | 0.8920 |
54 | 0.8920 |
54 | 0.8920 |
54 | 0.8920 |
53 | 3.7809 |
53 | 3.7809 |
53 | 3.7809 |
52 | 8.6698 |
51 | 15.5586 |
51 | 15.5586 |
49 | 35.3364 |
1978 | 149.8889 |
The value of test statistic t = 2.7383.
Alpha : Level of significance = 0.01
Since the test is right-tailed and value of test statistic is 2.7383, p-value is obtained by
p-value = P ( t n-1 > 2.7383) = P ( t 35 > 2.7383) = 0.0048
p-value = 0.0048
Decision : Since p-value is less than level of significance alpha, we reject Ho at 1% level of significance.
Conclusion: There is sufficient evidence support to claim that The bag will contain more than 54 candies.