Question

The grades of a science test are normally distributed. Thanh finds that his grade on the test has a z-score of –2.5. Which of the following statements must be true?

A. Thanh’s grade is 2.5 standard deviations below the mean of the test grades.

B. Thanh’s grade is 2.5 points below the mean of the test grades.

C. Thanh’s grade is 2.5 standard deviations above the mean of the test grades.

D. Thanh’s grade is 2.5 points above the mean of the test grades.

Answer 1

The right answer is Thanh's grade is 2.5 standard deviations below the mean of the test grades.

The z scores are standard deviations. If, for example, a tool returns a z score of +2.5, it means that the result is a standard deviation of 2.5.

Very high or very low (negative) z scores associated with very low p values are at the ends of the normal distribution.

Answer 2

Thanh's grade is 2.5 standard deviations below the mean of the test grades.

What is a Z-Score?

A z-score is the number of standard deviations from the mean of an information point. Be that as it may, even more is actually a proportion of the number of standard deviations below or above the population, which means a raw score. A z-score is called a standard score and can very well be placed on a common scatter curve.

With this information, we can conclude that Thanh's grade is 2.5 standard deviations below the mean of the test grades.

Learn more about Z-Score in brainly.com/question/15016913

#SPJ5