Question

On a standardized test, the mean score is 70, and the standard deviation is 10. If Rita Keane scored 90 on this test, her score is at what position in terms of standard deviations from the mean?

Answer 1

Rita Keane's score of 90 on a standardized test with a mean of 70 and a standard deviation of 10 is 2 standard deviations above the mean.

Step-by-step explanation:

To determine the position of Rita Keane's score in terms of standard deviations from the mean, we use the concept of a Z-score. A Z-score measures how many standard deviations an element is from the mean.

Given that the mean score on the test is 70 and the standard deviation is 10, Rita's score of 90 is 2 standard deviations above the mean. This is found by subtracting the mean from Rita's score and then dividing by the standard deviation: (90 - 70) / 10 = 2.

Therefore, Rita's score is 2 standard deviations above the mean. In a normally distributed graph, such as an IQ test graph, this would place her well above the average range.