Standard Error of the Mean, Confidence Intervals, & The Z Test
Report the values you are using for this assignment.
HR Mean (
µ
HR
)
(one decimal)
|
HR Std Dev (
s
HR
)
(two decimals)
|
RR Mean (
µ
RR
)
(one decimal)
|
RR Std Dev (
s
RR
)
(two decimals)
|
90.7
|
6.83
|
12.6
|
1.96
|
Make sure these initial values have been marked correct.
Follow the rounding instructions carefully.
Task 1: Standard Error of the Mean (SEM) for Different Sample Sizes
Imagine that your HR and RR data sets were very large (N=500). Calculate SEM based on the population standard deviations calculated in assignment 2, and the sample sizes given in the table.
Carefully round the SEM value to
2 decimals
for each calculation.
Formula:
Standard Error of the Mean
(SEM or
s
M
or
)
=
SEM
|
Heart Rate
|
Respiratory Rate
|
SEM if n = 9
|
2.28
|
0.65
|
SEM if n = 25
|
1.37
|
0.39
|
SEM if n= 100
|
0.68
|
0.2
|
What happens to the value of the SEM as the sample size increases?
By observing the values, we can conclude that as the sample size (n) increases the standard error of the mean decreases.
Question:
|
HR
|
RR
|
Sum of Squares (SS)
|
|
|
Using
the sample Variance is:
|
|
|
Using s
the unrounded sample standard deviation is
|
|
|
Rounded to 2 decimals
,
the sample Standard Deviation (s) is
|
|
|
Error check: Is your sample standard deviation greater than your sigma? (it should be)
|
|
|