Z = (raw score - mean)/standard deviation
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion in smallest area = .10. Insert that Z score and your other data in the equation above to get your answer.
Can someone assit me with my two math problems
Assume that the salaries of elementary school teachers in the united states are normally distributed with the mean of 36,000 and a standard deviation of 6,000. What is the cut off salary for teachers in the bottom 10%?
A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 40 seconds. The fitness association wants to recognize the fastest 10% of the boys with certificates of recognition. What time would the boys need to beat in order to earn a certificate of recognition from the fitness association?
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