Answer:
z-score for a value of 165 is + 1.73 times the standard deviation
The correct answer is B. 1.73
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Mean of the normal distribution = 143
Standard deviation = 12.7
2. What is the z-score of 165?
Let's recall that z-score in a normal distribution, positive or negative, is the number of times of the standard deviation a certain element is from the mean. If the element is below the mean, then the z-score is negative and if it's above the mean, then the z-score is positive.
Therefore, 165 will have the following z-score:
165 - 143 = 22 and it's above the mean.
Now, we calculate the z-score, using the value of the standard deviation this way:
22/12.7 = 1.73
z-score for a value of 165 is + 1.73 times the standard deviation
The correct answer is B. 1.73
