Question

The overall pass rate for law school graduates taking the Maryland bar exam has been reported as 76%. Assume that a certain Maryland law school has had 400 of its most recent graduates take the Maryland bar exam, but only 60% passed. When asked about these results, the dean of this university’s law school claims his graduates are just as good as others who have taken the Maryland bar exam, and the low pass rate for the recent graduates was just "one of those statistical fluctuations that happen all the time." If this university’s overall pass rate were really 76%, what would be the probability of a simple random sample of 400 having a pass rate of 60% or less

Answer 1

Answer:

The probability is $P(X \le 0.60) = 0.000$

Step-by-step explanation:

From the question we are told that

   The overall pass rate is  $R = 76\% = 0.76$

   The sample size is  n  =  400

   The percentage that passed is  $k = 60\% = 0.60$

Generally the standard error is mathematically represented as

     $\sigma _{\= x } = \sqrt{\frac{R (1 -R)}{n} }$    

  =>    $\sigma _{\= x } = \sqrt{\frac{0.76 (1 -0.76)}{400} }$

  =>    $\sigma _{\= x } = 0.0214$  

Generally the probability of a simple random sample of 400 having a pass rate of 60% or less is mathematically represented as

      $P(X \le 0.60) = P(\frac{X - R}{ \sigma_{\= x}} \le \frac{0.60 - 0.76}{0.0214} )$

=>   $P(X \le 0.60) = P(Z \le -7.48 )$

Generally from the z-table  

      $P(Z \le -7.48 ) = 0.000$

So

  $P(X \le 0.60) = 0.000$