Question

(a) the life spans of three randomly selected tires are 34,000 miles, 37,000 miles, and 31,000 miles that corresponds to each life span. for the life span of 34,000 miles, z-score is -1.63. (round to the nearest hundredth as needed.) for the life span of 37,000 miles, z-score is -0.41. (round to the nearest hundredth as needed.) for the life span of 31,000 miles, z-score is -2.86. (round to the nearest hundredth as needed.) according to the z-scores, would the life spans of any of these tires be considered unusual? ○ yes ○ no

Explanation:

To determine if a data point is unusual, we use the rule that z - scores with absolute values greater than 2 (or sometimes 3) are considered unusual. We check the absolute values of the given z - scores:

• For the z - score of - 1.63, the absolute value is $| - 1.63|=1.63<2$.
• For the z - score of - 0.41, the absolute value is $| - 0.41| = 0.41<2$.
• For the z - score of - 2.86, the absolute value is $| - 2.86|=2.86 > 2$.

Since there is a z - score ( - 2.86) with an absolute value greater than 2, the life span corresponding to this z - score (31,000 miles) is unusual. So the answer is Yes.

Answer:

Yes