221k views
1 vote
Suppose that the mean weight for men 18 to 25 years old is 172 pounds, and the standard deviation is 27 pounds. Assume that the weight for men 18 to 25 follows a normal distribution. In each part below, find the value of the z-score for the given weight. Round your answer to 2 decimal places.

(a) 210 pounds.
z =

(b) 148 pounds.
z =

(c) 170 pounds.
z =

(d) 233 pounds.
z =

1 Answer

4 votes

Explanation:

(a) To find the z-score for a weight of 210 pounds, we need to calculate how many standard deviations away from the mean this weight is. The formula for z-score is z = (x - mean) / standard deviation, where x is the given weight. Using the formula, we can calculate: z = (210-172)/27 Simplifying the calculation: z = 38/27 Rounding the answer to 2 decimal places: z = 1.41 Therefore, the z-score for a weight of 210 pounds is approximately 1.41. (b) To find the z-score for a weight of 148 pounds, we can use the same formula: z = (148-172) / 27 Calculating: z = -24 / 27 Rounding to 2 decimal places: z =-0.89 So, the z-score for a weight of 148 pounds is approximately -0.89. (c) For a weight of 148 pounds is approximately -0.89. (c) For a weight of 170 pounds: z = (170 - 172)/27 Simplifying: z = -2/27 Rounding to 2 decimal places: z = -0.07 Hence, the z-score for a weight of 170 pounds is approximately -0.07. (d) Finally, for a weight of 233 pounds: z = (233-172)/27 Calculating: z = 61/27 Rounding to 2 decimal places: z = 2.26 Thus, the z-score for a weight of 233 pounds is approximately 2.26. Hope this helps

User Saddam
by
8.0k points