Skittles Statistics teacher Jason Molesky contacted Mars, Inc., to ask about the color distribution for Skittles candies. Here is an excerpt from the response he received: “The original flavor blend for the SKITTLES BITE SIZE CANDIES is lemon, lime, orange, strawberry, and grape. They were chosen as a result of consumer preference tests we conducted. The flavor blend is 20 percent of each flavor.”

(a) State appropriate hypotheses for a significance test of the company’s claim.

(b) Find the expected counts for a bag of Skittles with 60 candies.

(c) How large a C2 statistic would you need to get in order to have significant evidence against the company’s claim at the A 0.05 level? At the A 0.01 level?

(d) Create a set of observed counts for a bag with 60 candies that gives a P-value between 0.01 and 0.05. Show the calculation of your chi-square statistic.

Short Answer

Expert verified

a)H0:pLemom=plime=pOrange=pSinaterry=pGinape=0.20

Ha:At least one of thepiis incorrect

b)The expected values are:

FlavourExpected countLemon60(0.2)=12Lime60(0.2)=12Orange60(0.2)=12Strawberry60(0.2)=12Grape60(0.2)=12

c)α=0.05,χ2=9.49

α=0.01,χ2=13.28

d)The test statistic is:10.1538

Step by step solution

01

Part (a) Step 1 Given Information

Given in the question that, The original flavor blend for the SKITTLES BITE SIZE CANDIES is lemon, lime, orange, strawberry, and grape. They were chosen as a result of consumer preference tests we conducted. The flavor blend is 20 percent of each flavor.

For a significance test of the company's claim, we must formulate acceptable hypotheses.

02

Part (a) Step 2 Explanation

From the given information, the null and alternative hypotheses are:

H0:plemom=pLime=pOrange=pSiraberry=pGirape=0.20

Ha: At least one of thepiis incorrect

03

Part (b) Step 1 Given Information

We need to calculate the expected counts for a bag of 60 Skittles.

04

Part (b) Step 2 Explanation

The expected values could be computed as:

FlavourExpected countLemon60(0.2)=12Lime60(0.2)=12Orange60(0.2)=12Strawberry60(0.2)=12Grape60(0.2)=12

05

Part (c) Step 1 Given Information

Given in the question that, the flavor blend is 20 percent of each flavor.

At the A 0.05 level, what size C2 statistic would you need to establish strong proof against the company's claim? At the level of A 0.01?

06

Part (c) Step 2 Explanation

We can calculate the degree of freedom as:

Degree of freedom=Number of categories-1=5-1=4.

Therefore, the critical values are:

localid="1653415588029" α=0.05,χ2=9.49From table

localid="1653415592837" α=0.01,χ2=13.28From table

Since the values are above the chi-square test statistic, we reject the null hypothesis and significant test.

07

Part (d) Step 1 Given Information

For a bag of 60 candies, we must produce a set of observed counts with a P-value between 0.01 and 0.05. Show your chi-square statistic computation.

08

Part (d) Step 2 Explanation

The test statistic can be calculated as:

Observed valueExpected value(O-E)(O-E)2(O-E)2/E610.4-4.419.361.8615610.4-4.419.361.86151610.4-240.41610.45.631.363.015410.45.631.363.0154

Therefore, the test statistic will be:

χ2=(O-E)2E=10.1538

This test statistic's p-value would be between 0.01and 0.05.

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