In: Statistics and Probability
Suppose a candy company representative claims that colored candies are mixed such that each large production batch has precisely the following proportions: 10% brown, 10% yellow, 30% red, 10% orange, 20% green, and 20%20% blue. The colors present in a sample of 410 candies was recorded. Is the representative's claim about the expected proportions of each color refuted by the data?
Color Number of Candies
brown 80
yellow 101
red 70
orange 60
green 39
blue 60
State the null and alternative hypothesis.
What does the null hypothesis indicate about the proportions of candies of each color?
State the null and alternative hypothesis in terms of the expected proportions for each category.
Find the expected value for the number of chocolate candies colored brown. Round your answer to two decimal places.
Find the expected value for the number of chocolate candies colored yellow. Round your answer to two decimal places.
Find the value of the test statistic. Round your answer to three decimal places
Find the degrees of freedom associated with the test statistic for this problem.
Find the critical value of the test at the 0.010.01 level of significance. Round your answer to three decimal places.
Make the decision to reject or fail to reject the null hypothesis at the 0.010.01 level of significance.
State the conclusion of the hypothesis test at the 0.010.01 level of significance.
Category | Observed Frequency (O) | Proportion, p | Expected Frequency (E) | (O-E)²/E |
Brown | 80 | 0.1 | 410 * 0.1 = 41 | (80 - 41)²/41 = 37.0976 |
Yellow | 101 | 0.1 | 410 * 0.1 = 41 | (101 - 41)²/41 = 87.8049 |
Red | 70 | 0.3 | 410 * 0.3 = 123 | (70 - 123)²/123 = 22.8374 |
Orange | 60 | 0.1 | 410 * 0.1 = 41 | (60 - 41)²/41 = 8.8049 |
Green | 39 | 0.2 | 410 * 0.2 = 82 | (39 - 82)²/82 = 22.5488 |
blue | 60 | 0.2 | 410 * 0.2 = 82 | (60 - 82)²/82 = 5.9024 |
Total | 410 | 1.00 | 410 | 184.996 |
Null and Alternative hypothesis:
Ho: Proportions are same as expected.
H1: Proportions are different.
Expected value for the number of chocolate candies colored brown = 410 * 0.1 = 41
Expected value for the number of chocolate candies colored yellow = 410 * 0.1 = 41
Test statistic:
χ² = ∑ ((O-E)²/E) = 184.996
df = n-1 = 5
Critical value:
χ²α = CHISQ.INV.RT(0.01, 5) = 15.086
Decision:
Reject the null hypothesis
Conclusion:
There is enough evidence to conclude that proportions are different at 0.01 significance level.