In: Statistics and Probability
Quiz vs Lecture Pulse Rates
Do you think your pulse rate is higher when you are taking a quiz
than when you are sitting in a lecture? The data in Table 1 show
pulse rates collected from 10 students in a class lecture and then
from the same students during a quiz. The data are stored in
QuizPulse10.
Student | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Mean | Std. Dev. |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Quiz | 75 | 52 | 52 | 80 | 56 | 90 | 76 | 71 | 70 | 66 | 68.8 | 12.5 |
Lecture | 73 | 53 | 47 | 88 | 55 | 70 | 61 | 75 | 61 | 78 | 66.1 | 12.8 |
Table 1 Quiz and lecture pulse rates for 10
students
Construct a 99% confidence interval for the difference in mean
pulse rate between students taking a quiz and sitting in a class
lecture.
sample size , n = 10
Degree of freedom, DF= n - 1 =
9 and α = 0.01
t-critical value = t α/2,df =
3.2498 [excel function: =t.inv.2t(α/2,df) ]
std dev of difference , Sd = √ [ (Di-Dbar)²/(n-1) =
9.9337
std error , SE = Sd / √n = 9.9337 /
√ 10 = 3.1413
margin of error, E = t*SE = 3.2498
* 3.1413 = 10.2087
mean of difference , D̅ =
2.700
confidence interval is
Interval Lower Limit= D̅ - E = 2.700
- 10.2087 = -7.509
Interval Upper Limit= D̅ + E = 2.700
+ 10.2087 = 12.909
so, confidence interval is (
-7.5087 < µd < 12.9087
)
Please revert in case of any doubt.
Please upvote. Thanks in advance