Question 305833: The Gibbs Baby Food Company wishes to compare the weight gain of infants using their brand versus their competitor’s brand. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first 3 months after birth. The standard deviation of this sample is 2.3 pounds. A sample of 55 babies using the competitors brand revealed a mean increase of 8.8 pounds with a standard deviation of 2.9 pounds. At 95% level of confidence, can we conclude that the babies using the Gibbs product gained LESS weight? Z-test for Unpaired data
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The Gibbs Baby Food Company wishes to compare the weight gain of infants using their brand versus their competitor’s brand. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first 3 months after birth. The standard deviation of this sample is 2.3 pounds. A sample of 55 babies using the competitors brand revealed a mean increase of 8.8 pounds with a standard deviation of 2.9 pounds. At 95% level of confidence, can we conclude that the babies using the Gibbs product gained LESS weight? Z-test for Unpaired data
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I used a 2-Sample Z Test and got the following interval:
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-2.247 < u < -0.1534
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Since the interval does not contain zero, we can conclude
the Gibbs group gained Less weight.
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Cheers,
Stan H.
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