In: Statistics and Probability
Assume that 85% of STAT 207 students pass the course. If a random sample of 160 STAT 207 students is taken, find the probability that at least 130 of them pass the course?
P[ STAT 207 students pass the course ] = 85% = 0.85
Number of students = 160
Proportion = 130/160 = 0.8125
The following information has been provided about the population proportion and the sample size:
Population Proportion = | 0.85 |
Sample Size = | 160 |
We need to compute . Based on the information provided, the population men of sample proportions and the corresponding standard error are:
Observe that:
which indicates that the assumption for normal approximation for the sampling distribution is met.
Now, the following is obtained using normal approximation:
= 0.908
P[ umber of students passing more than 130 ] = 0.908