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Assume z is a standard normal random variable. Then P (1.55≤z≤2.17) equals a. 0.9544 b. 0.9244 c. 0.4244 d. 0.0456

User Chrystolin
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Final answer:

To calculate P(1.55≤z≤2.17), find the area to the left for each z-score from a standard normal distribution table and subtract the smaller from the larger area.

Step-by-step explanation:

The question asks to calculate the probability P(1.55≤z≤2.17) given that z is a standard normal random variable. To find this, we look at the standard normal distribution table or use statistics software. First, find the area to the left of z = 2.17, which we denote as A(2.17), and the area to the left of z = 1.55, which is A(1.55).

Next, the probability that z is between 1.55 and 2.17 is the difference between these two areas, calculated as P(1.55≤z≤2.17) = A(2.17) - A(1.55). Using a z-table or appropriate software will yield this probability.

This requires finding the separate areas from the table and then subtracting the smaller from the larger to find the probability of z falling between the two values.

User Jack Gajanan
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