Sue took a test in both biology and math last week.The biology test had a mean of 70 and a standard deviation of 7 whereas the math test had a mean of 75 and a standard deviation of 10.Sue scored a 76 on the biology test and a 76 on the math test.On which test did she do better in comparison to the rest of the class?
A)the math test
B)the biology test
C)she did the same on each test
D)cannot be determined

Question

Quizplus · Accepted Answer

To find out which test Sue did better on, we need to compare her scores to the rest of the class. To do this, we will convert Sue's scores to z-scores using the formulas: z = (x - mean) / standard deviation. For the biology test, Sue's z-score is (76 - 70) / 7 = 0.86. For the math test, Sue's z-score is (76 - 75) / 10 = 0.1. A higher z-score means the score is farther from the mean, indicating better performance relative to the rest of the class. Since Sue's z-score is higher for the biology test, we can conclude that she did better on the biology test compared to the rest of the class. Thus, the answer is B, the biology test.

Sue Took a Test in Both Biology and Math Last