Answer: To determine whether Rachel's z-score will be positive or negative, we first need to convert her height from feet and inches to inches.
Since there are 12 inches in one foot, Rachel's height in inches can be calculated as:
5 feet x 12 inches/foot + 5 inches = 60 inches + 5 inches = 65 inches
To calculate Rachel's z-score, we can use the formula:
z = (x - μ) / σ
where x is the raw score (in this case, Rachel's height of 65 inches), μ is the population mean (64 inches), and σ is the population standard deviation (2.5 inches).
Substituting the values, we get:
z = (65 - 64) / 2.5
z = 0.4
Since Rachel's height is greater than the mean, her z-score will be positive.
Therefore, the answer is: Positive.
Explanation: