The grades on exam C are normally distributed with a population mean of 75% and a population standard deviation of 5%. Select the best statement: a. The 95% confidence interval on the exam C distribution extends from 65% to 85%. b. 34% of the grades on exam C are between 75% and 80%. c. 65% of the grades on exam C are between 65% and 85%. d. The area under the entire curve of exam C grades could be less than 100%.
Added by Stephen C.
Step 1
A normal distribution is symmetric about its mean, and the total area under the curve represents the probability of all possible outcomes, which is 100%. The standard deviation (SD) measures the dispersion of data points around the mean. Show more…
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