Question

SOLVE #10 please!

Question 8 8 out of 8 points The registrar at Fort Lewis College suspects that business school students are missing too much class. In order to test his claim, the registrar takes a simple random sample of six students. For a random sample of students, the number of days each was absent from their classes during the Fall 2014 semester was recorded. The data are listed below. 3 2 1 0 2 7 For a 99% confidence interval estimate for the mean number of days absent, give the value of the upper bound. Round to three decimal places. Question 9 8 out of 8 points The registrar at Fort Lewis College suspects that business School students are missing too much class. In order to test his claim, the registrar takes a simple random sample of six students. For a random sample of students, the number of days each was absent from their classes during the Fall 2014 semester was recorded. The data are listed below. 3 7 2 1 0 2 For a 99% confidence interval estimate for the mean number of days absent, give the value of the lower bound. Round to three decimal places. Question 10 Needs Grading Use your results from the two previous questions (the upper and lower limits for the 99% confidence interval for the mean number of days absent) to answer this question. The registrar suspects that on average, students are missing about three classes per semester. Do you agree with the registrar? Explain your reasoning.

Answer 1

	x	x2
	3	9
	7	49
	2	4
	1	1
	0	0
	2	4
Total	15	67

n=6

Sample mean =

15 EL Σ f

= 2.5

The standard deviation of sample is given by

Σχ2 (Σx) n S = η –1

67- (15) 6 S= 6-1

67 – 37.5 S = 5

S = 5.9

S = 2.43

The 99% confidence interval of mean is given by

x+ta/2, -1) * se(x)

s i t 0.995,5) vn

2.43 2.5 + 4.032143 16

2.5 +3.998

Lower bound= -1.498

Upper bound = 6.498

Answer(8):

Upper bound = 6.498

Answer(9):

Lower bound= -1.498

Answer(10):

We have obtained the 99% confidence interval for the mean number of days absent which is (-1.498, 6.498).

The registrar suspects on average, students are missing about three classes per semester. In the above confidence interval the value 3 is included which indicates that the 3 days is not significantly different from the mean number of days absent.

Hence we can say that the registrar is right about the mean number of days absent with 99% confidence and we can agree with registrar.