In: Math
A coworker claims that Skittles candy contains equal quantities
of each color (purple, green, orange, yellow, and red). In other
words, 1/5 of all Skittles are purple, 1/5 of all Skittles are
green, etc. You, an avid consumer of Skittles, disagree with her
claim. Test your coworker's claim at the α=0.10α=0.10 level of
significance, using the data shown below from a random sample of
200 Skittles.
Which would be correct hypotheses for this test?
H0:H0: Red Skittles are cherry flavored; H1:H1: Red Skittles are strawberry flavored
H0:H0:Skittles candy colors come in equal quantities; H1:H1:Skittles candy colors do not come in equal quantities
H0:H0:Taste the Rainbow; H1:H1:Do not Taste the Rainbow
H0:p1=p2H0:p1=p2; H1:p1≠p2H1:p1≠p2
Sample Skittles data:
Color | Count |
---|---|
Purple | 38 |
Green | 34 |
Orange | 38 |
Yellow | 39 |
Red | 51 |
Test Statistic:
Give the P-value:
Which is the correct result:
Reject the Null Hypothesis
Do not Reject the Null Hypothesis
Which would be the appropriate conclusion?
There is not enough evidence to reject the claim that Skittles colors come in equal quantities.
There is not enough evidence to support the claim that Skittles colors come in equal quantities
Solution:-
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
Null hypothesis: H0: Skittles candy colors come in equal quantities.
Alternative hypothesis: H1: Skittles candy colors do not come in equal quantities.
Formulate an analysis plan. For this analysis, the significance level is 0.10. Using sample data, we will conduct a chi-square goodness of fit test of the null hypothesis.
Analyze sample data. Applying the chi-square goodness of fit test to sample data, we compute the degrees of freedom, the expected frequency counts, and the chi-square test statistic. Based on the chi-square statistic and the degrees of freedom, we determine the P-value.
DF = k - 1 = 5 - 1
D.F = 4
(Ei) = n * pi
X2 =
4.15
where DF is the degrees of freedom, k is the number of levels of the categorical variable, n is the number of observations in the sample, Ei is the expected frequency count for level i, Oi is the observed frequency count for level i, and X2 is the chi-square test statistic.
The P-value is the probability that a chi-square statistic having 4 degrees of freedom is more extreme than 4.15
We use the Chi-Square Distribution Calculator to find P(X2 > 4.15) = 0.386
Interpret results. Since the P-value (0.386) is greater than the significance level (0.10), we have to accept the null hypothesis.
Do not Reject the Null Hypothesis.
There is not enough evidence to reject the claim that Skittles colors come in equal quantities.