Researchers at Purdue University and Wichita State University found that airline

Question

Researchers at Purdue University and Wichita State University found that airlines are doing a better job getting passengers to their destinations on time. AirTran Airways and Southwest Airlines were among the leaders in on-time arrivals, with both having 88% of their flights arriving on time. But for the 12% of flights that were delayed, how many minutes were these flights late? Sample data showing the number of minutes that delayed flights were late are provided in the data below: A. Develop the null and alternative hypothesis that can be used to test for a difference between population mean minutes late for delayed flights by these two airlines. B. What is the sample mean number of minutes late for delayed flights for each these two airlines? C. Using a 5% level of significance, what is your conclusion?

AirTran Southwest 34 45 59 64 43 42 30 33 3 66 32 105 42 45 85 28 30 38 48 85 110 75 50 45 10 33 26 50 70 63 52 42 83 35 78 33 27 64 70 65 27 90 38 52 76 excel data info

Explanation / Answer

Given that,
AirTran
mean(x)=50.6 , standard deviation , s.d1=26.57, number(n1)=25

Southwest
y(mean)=52.8, standard deviation, s.d2 =20.11, number(n2)=20

null, Ho: u1 = u2
alternate, H1: u1 != u2
level of significance, = 0.05
from standard normal table, two tailed t /2 =2.093
since our test is two-tailed
reject Ho, if to < -2.093 OR if to > 2.093
we use test statistic (t) = (x-y)/sqrt(s.d1^2/n1)+(s.d2^2/n2)
to =50.6-52.8/sqrt((705.9649/25)+(404.4121/20))
to =-0.316
| to | =0.316
critical value
the value of |t | with min (n1-1, n2-1) i.e 19 d.f is 2.093
we got |to| = 0.31603 & | t | = 2.093
make decision
hence value of |to | < | t | and here we do not reject Ho
p-value: two tailed ( double the one tail ) - Ha : ( p != -0.316 ) = 0.755
hence value of p0.05 < 0.755,here we do not reject Ho
ANSWERS
---------------
a.
null,no significance in mean between them Ho: u1 = u2
alternate,difference between population mean minutes late for
delayed flights by these two airlines H1: u1 != u2
b.
AirTran
mean(x)=50.6 , standard deviation , s.d1=26.57, number(n1)=25

Southwest
y(mean)=52.8, standard deviation, s.d2 =20.11, number(n2)=20

c.
test statistic: -0.316
critical value: -2.093 , 2.093
decision: do not reject Ho
p-value: 0.755

no difference between population mean minutes late for
delayed flights by these two airlines

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.