posted by suhad .
3. In a sample of 64 students given an examination in statistics, it is found that the mean weight is 57 kg with standard deviation 9 kg. Find :
ƒÜ i) The proportion of students weight 48-62 kg.
ƒÜ ii) The proportion of those less than 72 kg.
ƒÜ iii) The proportion of those less than 50 kg ?
ƒÜ iv) If the highest 5% of are over-weight, what is the Minimum score for an over-weight.
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability for the Z scores.
For last problem, find Z score for 5% in smaller area and use its Z score.