The office of student services at a large western state university maintains information on the study habits of its full-time st
udents. their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. the hours studied follows the normal distribution with a standard deviation of six hours. suppose we select a random sample of 144 current students. what is the probability that the mean of this sample is less than 19.25 hours? g
1 answer:
A suitable probability calculator can tell you the probability is about 6.7%.
_____
The standard deviation of the distribution of sample means is the population standard deviation (6) divided by the square root of the sample size (√144=12). Thus, your threshold is about (19.25-20)/(6/12) = -1.5 standard deviations from the mean.
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Let x represent number of wrong questions answered by Aaron.
We have been given that Aaron is taking a multiple choice test with a total of 20 points available. Each question is worth exactly 1 point. We are asked to find Aaron's score (out of 20) if he got 6 questions wrong.
To find Aaron's score, we will subtract number of wrong answers from total score.
Therefore, Aaron's test scores would be 14 out of 20.
To find Aaron's score if he got x questions wrong, we will subtract x from total scores that is .
Therefore, Aaron's score would be , if he got x questions wrong.