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the percentage probability that a student will score more than 90%in an accounting exam is 60%.
the marks scored from the accounting exam follow a standard normal distribution with a mean mark of 70%.what is the standard deviation for the distribution ?
sir in this question which i have created
will the below be the answer
Z = 1 – 0.6 = 0.4
so from the table = 1.28z score = x – the mean / standard deviation
so
20/1.28 = 15.625is the answer correct as per what i have done sir
will the standard deviation be 15.625 ?
The question as you have typed it is impossible.
Given that the distribution is symmetrical about the mean, there is a 50% probability of them scoring more than 70% in the exam.
The probability of them scoring more than 90% in the exam must therefore be less than 50%. It cannot be more than 50%.
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