Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Explanation:

i) mean number of defective bulbs per case

ii) Ha : μ > 20

From the given output:

iii) 1.3006

iv) Null hypothesis is rejected because p-value = 0.021 < 0.10.

v) risk of committing of a type1 error is alpha = 0.10.

vi) Yes, there is sufficient evidence that the mean number of defective bulbs per case is greater than 20 during the morning shift.

vii) The manager can conclude that the mean number of defective bulbs per case during the morning shift is greater than 20 using a level of significance of 0.10.

viii) for two tailed test, p-value would be double.

p-value=2(0.021)={\color{Red} 0.042}

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