Exhibit 8-5
A random sample of 64 SAT scores of students applying for merit scholarships showed an average of 1400 with a standard deviation of 240.
-Refer to Exhibit 8-5. The 95% confidence interval for the SAT scores is
A)1340.05 to 1459.95
B)1400 to 1459.95
C)1340.05 to 1400
D)1400 to 1600

Question

Quizplus · Accepted Answer

Using a 95% confidence level and a sample size of 64, the t-value is 1.99. Therefore, the margin of error is 1.99 * (240/sqrt(64)) = 59.85. The confidence interval is (1400 - 59.85, 1400 + 59.85), which simplifies to (1340.15, 1459.85). Rounding to two decimal places gives us a 95% confidence interval of (1340.05, 1459.95). Therefore, the best choice is A.

Exhibit 8-5 A Random Sample of 64 SAT Scores of Students Applying