Final answer:
Ginny's three test scores, calculated from a median of 91, a mean of 83, and a range of 28, were 60.5, 91, and 88.5.
Step-by-step explanation:
Ginny's median score on three tests was 91, her mean score was 83, and her range was 28. To find her three test scores, we can set up a system of equations. Since the median score is 91, one of her scores is 91. Let's call her other two scores A and B, and without loss of generality, let's assume A < B. We can now express the mean as (A + 91 + B)/3 = 83, giving us A + B = 149 after multiplying through by 3 and subtracting 91 from both sides.
The range of her test scores is the difference between the highest and lowest, which is given as 28. Since we assumed A < B, then B - A = 28. We now have two equations: A + B = 149 and B - A = 28. Adding these two equations gives us 2B = 177, which simplifies to B = 88.5. Subtracting the second equation from the first gives us 2A = 121, which simplifies to A = 60.5.
Therefore, Ginny's three test scores were 60.5, 91 (the median), and 88.5.