Statistics?

[Moses Paul]

ial statistics?
b) Scores in a mathematics exam form a normal distribution with a mean of 60 and a standard deviation of 8.0
what would be the percentile rank of Hillary who obtained a raw score of 72
what would be the percentile rank of Jane who obtained a raw score of 55

if there were a total of n=500 candidates, how many students scored between Hillary’s and jane’s scores

which scores form the middle 40% in this score distribution

what would be the cut-off score if only 125 students are to be selected for a competitive programme

 

[Deleted member 4993]

ial statistics?
b) Scores in a mathematics exam form a normal distribution with a mean of 60 and a standard deviation of 8.0
what would be the percentile rank of Hillary who obtained a raw score of 72
what would be the percentile rank of Jane who obtained a raw score of 55

if there were a total of n=500 candidates, how many students scored between Hillary’s and jane’s scores

which scores form the middle 40% in this score distribution

what would be the cut-off score if only 125 students are to be selected for a competitive programme

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[HallsofIvy]

ial statistics?
b) Scores in a mathematics exam form a normal distribution with a mean of 60 and a standard deviation of 8.0
what would be the percentile rank of Hillary who obtained a raw score of 72
what would be the percentile rank of Jane who obtained a raw score of 55

if there were a total of n=500 candidates, how many students scored between Hillary’s and jane’s scores

which scores form the middle 40% in this score distribution

what would be the cut-off score if only 125 students are to be selected for a competitive programme

Are you taking a course in statistics? If not, where did you get these problems? If yes, then you should know what a "normal distribution" is and what "mean" and "standard distribution" mean. Here the mean is 60 and the standard distribution is 8. A score of 72 is 72- 60= 12 points above the mean so 12/8= 1.5 standard distributions above the mean. Do you understand how to find the probability of "1.5 standard distributions above the mean"? You cannot calculate that, you look it up in a table of the normal distribution.

55 is 60- 55= 5 points below the mean so 5/8= 0.625 standard distributions below the mean. What is the probability of "0.625 standard distributions below the mean"?

If this is a total of 500 people then the number of people is those probabilities (thought of as precentages) times 500.

There is a nice table at
Standard Normal Distribution Table (mathsisfun.com)