Question

Scores for an exam are normally distributed with a mean of 235 and a standard deviation of 52. What is the percentile value of a score of 270? Round your score to TWO decimal places. For example, if you compute a value of .547, you would enter .55. ALSO: Please enter ONLY the value, no equals sign, no words, etc.

Answer 1

Solution :

Given that ,

mean =  $\mu$ = 235

standard deviation = $\sigma$ = 52

P(X< 270) = P[(X- $\mu$ ) / $\sigma$ < (270-235) /52 ]

= P(z <0.67 )

Using z table

=0.7486

=74.86%

=74.86