(d)Construct separate 90% confidence intervals for each mean. Monthly rent paid by undergraduates and graduate students.
Undergraduate Student Rents (
n
= 10)
820
780
870
670
800
790
810
680
1,000
730
Graduate Student Rents (
n
= 12)
1,130
920
930
880
780
910
790
840
930
910
860
850
a) Construct a 95 percent confidence interval for the difference of mean monthly rent paid by undergraduates and graduate students using the assumption of unequal variances with Welch's formula for d.f.Welch’s d.f.= 18 (calculated from MegaStat) and the tstatistic = 2.101(795894.17)±2.101 根根根9093.5296/10+8136.04/12
根
Surgeon 1
Surgeon 2
Surgeon 3
Surgeon 4
Surgeon 5
Old way
36
55
28
40
62
New way
29
42
30
32
56
(a1)Calculate the difference between the new and the old ways for the data given below. Use α = .05.(Negative values should be indicated by a minus sign.)
X
1
X
2
X
1

X
2
Surgeon
Old Way
New Way
Difference
1
36
29
2
55
42
3
28
30
4
40
32
5
62
56
(a2)Calculate the mean and standard deviation for the difference. (Round your mean answer to 1 decimal place and standard deviationanswer to 4 decimal places.)MeanStandard Deviation(a3)Choose the right option for H0:μd≤ 0; H1:μd> 0.Reject if tα> 2.132(a4)Calculate the value of t. (Round your answer to 4 decimal places.)tcalc(b1)Is the decision close? (Round your answer to 4 decimal places.)
.
True(b3)The difference is significant.
Define the difference as Old – New.
d.f.
(b)The decision is not close. The pvalue is .0287 =T.DIST.RT(2.6439,4), which is less than .05, and thetcalcwas well within the rejection reMonthly rent paid by undergraduates and graduate students.Undergraduate Student Rents (n= 10)760760880710680830750610980690Graduate Student Rents (n= 12)1,150900910890720920800780890900920800Click here for the Excel Data File(a) Construct a 98 percent confidence interval for the difference of mean monthly rent paid by undergraduates and graduate students, using the assumption of unequal variances with Welch's formula for d.f.(Do not round the intermediate calculations.Round your final answers to 3 decimal places. Negative values should be indicated