Gibbs Baby Food Company wishes to compare the weight gain of infants using its brand versus its competitor's. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first three months after birth. For the Gibbs brand, the population standard deviation of the sample is 2.3 pounds. A sample of 55 babies using the competitor's brand revealed a mean increase in weight of 8.1 pounds. The population standard deviation is 2.9 pounds. State the decision rule for 0.05 significance level : H0: μ;Gibbs ≥ μ;Competitor; H1: μGibbs < μ;Competitor. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.) Compute the value of the test statistic. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.) Compute the p-value. (Round your answer to 4 decimal places.) Can we conclude that babies using the Gibbs brand gained less weight? Use the 0.05 significance level.

Determine the decision rule at the 0.05 level of significance. That is, there is no evidence to conclude that the babies using the Gibbs brand gained less weight. That is, there is evidence to conclude that the babies using the Gibbs brand gained less weight.Obtain the critical value of z at the 95% confidence level. Here, confidence level is 0.95. Use EXCEL Procedure for finding the critical value of z. Follow the instruction to obtain the critical value of z: Open EXCEL Go to Formula bar. In formula bar enter the function as“=NORMINV” Enter the probability as 0.05. Enter the mean as 0 and the Standard deviation as 1. Click enter EXCEL output: From the EXCEL output, the critical value of z at the 95% confidence level is –1.645. Obtain the value of the test statistic. The value of the test statistic is obtained below as follows: From the information, given that Thus, the value of the test statistic is –0.94.Obtain the P-value. Use Excel to obtain the probability value for z =–0.94. Follow the instruction to obtain the P-value: Open EXCEL Go to Formula bar. In formula bar enter the function as“=NORMSDIST” Enter the test statistic z as –0.94 Click enter EXCEL output: From the Excel output, the P-value is 0.1736 Thus, the P-value is 0.1736. Conclusion: The conclusion is obtained as shown below: Use the level of significance is 0.05. The p-value is greater than level of significance. By rejection rule, do not reject the null hypothesis. That is, there is no evidence to conclude that the babies using the Gibbs brand gained less weight.

Answered: Gibbs Baby Food Company wishes to…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Gibbs Baby Food Company wishes to compare the weight gain of infants using its brand versus its competitor's. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first three months after birth. For the Gibbs brand, the population standard deviation of the sample is 2.3 pounds. A sample of 55 babies using the competitor's brand revealed a mean increase in weight of 8.1 pounds. The population standard deviation is 2.9 pounds.

State the decision rule for 0.05 significance level : H₀: μ;_Gibbs ≥ μ;_Competitor; H₁: μ_Gibbs < μ;_Competitor. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.)

Compute the value of the test statistic. (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.)

Compute the p-value. (Round your answer to 4 decimal places.)

Can we conclude that babies using the Gibbs brand gained less weight? Use the 0.05 significance level.

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