A random sample of 150 students has a grade point average wi
A random sample of 150 students has a grade point average with a standard deviation of 0.78. Find the margin of error if cequals=0.98.
Solution
Margin of Error = Z a/2 * (sd/ Sqrt(n))
 Where,
 x = Mean
 sd = Standard Deviation
 a = 1 - (Confidence Level/100)
 Za/2 = Z-table value
 Mean(x)=25.5
 Standard deviation( sd )=0.78
 Sample Size(n)=150
 Margin of Error = Z a/2 * 0.78/ Sqrt ( 150)
 = 2.33 * (0.064)
 = 0.148

