The director of admissions at the University of Maryland, University College is
ID: 3357390 • Letter: T
Question
The director of admissions at the University of Maryland, University College is concerned about the high cost of textbooks for the students each semester. A sample of 25 students enrolled in the university indicates that x(bar) = $315.40 and s = $43.20. Using the .5 level of significance, is there evidence that the population mean is above $300?
A. No because 300 is below the lower limit of the confidence interval
B. Yes, because 300 is below the lower limot of the confidence interval
C. No because 300 is the confidence interval
D. Yes because 300 is in the confidence interval.
Explanation / Answer
x' = 315.40 s = 43.20
n = 25 z = 1.96
Upper limit for = 315.40 + 1.96 * 43.20 / 25
= 332.3344
Lower limit for = 315.40 - 1.96 * 43.20 / 25
= 298.4656
The answer is D. Yes, because 300 is in the inteval.