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: 30% brown, 10% yellow, 20% red, 10% orange, 10% green, and 20% blue. The colors present in a sample of 452 candies was recorded. Is the representative's claim about the expected proportions of each color refuted by the data?
Chart: Brown goes with 72 and green goes with 112. Etc...
Color- Brown, yellow, red, orange, green, blue
Number of candies- 72, 67, 67, 67, 112, 67
Step 1: State the null and alternative hypothesis
Step 2: What does the null hypothesis indicate about the proportions of candies of each color?
Step 3: State the null and alternative hypothesis in terms of the expected proportions of each category.
Step 4: Find the expected value for the number of chocolate candies colored brown. Round your answer to two decimal places.
Step 5: Find the expected value for the number of chocolate candies colored green. Round your answer to two decimal places.
Step 6: Find the value of the test statistic. Round your answer to three decimal places.
Step 7: Find the degrees of freedom associated with the test statistic for this problem.
Step 8: Find the critical value of the test at the 0.01 level of significance. Round your answer to three decimal places.
Step 9: Make the decision to reject or fail to reject the null hypothesis at the 0.01 level of significance.
Step 10: State the conclusion of the hypothesis test at the 0.01 level of significance.
Is or is not enough evidence to refute the company's claim about proportions of colored candies.
Result:
Step 1: State the null and alternative hypothesis
Ho: the proportions of candies of each color are in expected proportions
H1: the proportions of candies of each color are not in expected proportions
Step 2: What does the null hypothesis indicate about the proportions of candies of each color?
Expected proportions: 30% brown, 10% yellow, 20% red, 10% orange, 10% green, and 20% blue
Step 3: State the null and alternative hypothesis in terms of the expected proportions of each category.
Ho: the proportions of candies of each color are in expected proportions
H1: the proportions of candies of each color are not in expected proportions
Step 4: Find the expected value for the number of chocolate candies colored brown. Round your answer to two decimal places.
135.60
Step 5: Find the expected value for the number of chocolate candies colored green. Round your answer to two decimal places.
45.20
Step 6: Find the value of the test statistic. Round your answer to three decimal places.
161.695
Step 7: Find the degrees of freedom associated with the test statistic for this problem.
5
Step 8: Find the critical value of the test at the 0.01 level of significance. Round your answer to three decimal places.
15.086
Step 9: Make the decision to reject or fail to reject the null hypothesis at the 0.01 level of significance.
Since calculated chi square 161.695 > critical chi square 15.086, Ho is rejected.
Step 10: State the conclusion of the hypothesis test at the 0.01 level of significance.
There is enough evidence to refute the company's claim about proportions of colored candies.
color |
Number of candies |
percentage |
expected |
Brown |
72 |
30 |
(30/100)*452=135.60 |
yellow |
67 |
10 |
(10/100)*452=45.20 |
red |
67 |
20 |
(20/100)*452=90.40 |
orange |
67 |
10 |
(10/100)*452=45.20 |
green |
112 |
10 |
(10/100)*452=45.20 |
blue |
67 |
20 |
(20/100)*452=90.40 |
452 |
Goodness of Fit Test |
||||
observed |
expected |
O - E |
(O - E)² / E |
|
72 |
135.600 |
-63.600 |
29.830 |
|
67 |
45.200 |
21.800 |
10.514 |
|
67 |
90.400 |
-23.400 |
6.057 |
|
67 |
45.200 |
21.800 |
10.514 |
|
112 |
45.200 |
66.800 |
98.722 |
|
67 |
90.400 |
-23.400 |
6.057 |
|
Total |
452 |
452.000 |
161.695 |
|
161.695 |
chi-square |
|||
5 |
df |