The U.S. Golf Association (USGA) requires that golf balls have a diameter that is 1.68 inches. To determine if Maxfli XS golf balls conform to USGA standards, a random sample of Maxfli XS golf balls was selected. Their diameters are shown in the table.

1.683

1.684

1.677

1.684

1.681

1.673

1.685

1.685

1.678

1.682

1.686

1.674

1 Because the sample size is small, the engineer must verify that the diameter is normally distributed and the sample does not contain any outliers. The normal probability plot and boxplot are shown. The correlation between ball diameter and expected z-scores is 0.951.

2 Are the conditions for testing the hypothesis satisfied?

3 Construct a 95% confidence interval to judge whether the golf balls conform to USGA standards. Be sure to state the null and alternative hypotheses and write the conclusion.

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