Question

500 hearing impaired children took a multiple choice hearing test and scored a mean of 50 and a standard deviation of 20. assuming a normal distribution of scores what % of children scored between 40 & 90

Answer 1

To find the percentage of children who scored between 40 and 90 on the hearing test, calculate the z-scores for each score and use the standard normal distribution table to determine the percentage. Approximately 52.95% of the children scored between 40 and 90 on the hearing test.

Step-by-step explanation:

To find the percentage of children who scored between 40 and 90 on the hearing test, we need to calculate the z-scores for each score and then use the standard normal distribution table to determine the percentage.

First, calculate the z-score for a score of 40: z = (40 - 50) / 20 = -0.5.

Next, calculate the z-score for a score of 90: z = (90 - 50) / 20 = 2.

Using the standard normal distribution table, we find that the percentage of children with a z-score between -0.5 and 2 is approximately 52.95%.

So, approximately 52.95% of the children scored between 40 and 90 on the hearing test.