A Severe Drought Affected Several Western States for 3 Years

question 112

Multiple Choice

A severe drought affected several western states for 3 years. A Christmas tree farmer is worried about thedroughtʹs effect on the size of his trees. To decide whether the growth of the trees has been retarded, the farmerdecides to take a sample of the heights of 25 trees. Typically trees of this age have a mean height of 65 incheswith a standard deviation of 9 inches. Assuming the distribution is bell shaped, where do you expect middle95% of the tree heights to fall?

• A) between 47 and 83 inches tall
• B) between 56 and 74 inches tall
• C) between 38 and 92 inches tall
• D) over 56 inches tall

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Definitions:

One-tail

One-tail refers to one-sided tests in hypothesis testing where the critical area of a distribution is one-sided, either to the right or left, focusing on a specific direction of interest.

Two-tail

A term used in statistical tests where the critical region is split between both ends of the distribution, testing for either significantly greater or lesser outcomes than the expected value.

Kruskal-Wallis Test

A non-parametric method for testing whether samples originate from the same distribution, often used as an alternative to one-way ANOVA when the assumptions of ANOVA are not met.

ANOVA F Test

A statistical test used to determine if there are any statistically significant differences between the means of three or more independent groups.