Providing an appropriate response

Question

A student wished to use a table of areas for the standard normal curve to find the z-score having an area to its right of 0.52. The student started by looking for the closest area to 0.52 in the body of the table and reading off the corresponding z-score which was 0.05. She then subtracted this z-score from 1 to get 0.95. Was her reasoning correct? If not, where did she go wrong and how would you have solved the problem?



A psychologist wishes to estimate the mean IQ of students at one college. He picks a random sample of 49 students from the college, measures each student's IQ, and obtains the following 95% confidence interval for the population mean, μ: 115 to 125. How would you interpret this confidence interval?

Answer 1

Obtain a z-score table:

http://www.utdallas.edu/dept/abp/zscore

 

In a z-score table all decimals (percentages) are state the area to the right of the z-score.

In the table the closest number to 0.52 is 0.5199 that has a z-score of 0.05.

She should have stopped here.