Question

I am very lost on this. If there is an Excel formula I could use, that would help tremendously. Thank you... Create confidence intervals related to the interval and ratio-level data you collected.
1. What is the best estimate of the population mean
2. Develop a 95% confidence interval for the population mean. Develop a 90% confidence interval for the population mean. Develop a 98% confidence interval for the population mean.
3. Interpret the confidence interval.
Create an individual Excel document for each of the required items.
APA format is not required, but solid academic writing is expected. I have all my numbers but I am very unsure of how to go about this. Is there an Excel formula to calculate this. Here are my numbers: Breakfast I came up with the mean as 4.4505
$1.07
$1.59
$1.81
$2.13
$2.14
$2.45
$2.88
$3.21
$3.40
$3.51
$3.63
$3.73
$3.84
$4.27
$4.28
$4.70
$4.90
$5.33
$5.34
$5.35
$5.54
$5.66
$5.76
$5.77
$6.09
$6.30
$6.42
$6.62
$6.73
$6.92
$6.94
$7.03
$7.47
$7.48
$7.69
$7.78
$8.25
$8.43
$8.66
$11.32
$11.52
$13.25
$13.89
$15.95 Lunch I came up with the mean as 7.9955
2.13
2.99
4.15
4.27
4.28
4.28
4.28
4.47
5.21
5.33
5.35
5.35
5.35
5.35
5.54
5.65
5.75
5.87
6.29
6.39
6.41
6.42
6.42
6.42
6.42
6.42
6.51
6.51
6.71
7.05
7.05
7.05
7.35
7.45
7.56
7.69
7.80
7.80
8.01
8.11
8.22
8.22
8.86
8.96
9.26
9.35
9.37
9.39
9.82
11.01
11.10
11.41
11.73
12.17
13.57
15.34
15.78
16.22
18.28
22.21

Answer 1

Sol:

in excel

install analysis toolpak an then go to

Data >data analysis>Descriptive statistcs

you will get

Breakfast		lunch
Mean	6.068864	Mean	7.995167
Standard Error	0.495797	Standard Error	0.484616
Median	5.71	Median	7.05
Mode	#N/A	Mode	6.42
Standard Deviation	3.288743	Standard Deviation	3.753818
Sample Variance	10.81583	Sample Variance	14.09115
Kurtosis	1.370727	Kurtosis	3.306239
Skewness	1.075678	Skewness	1.642936
Range	14.88	Range	20.08
Minimum	1.07	Minimum	2.13
Maximum	15.95	Maximum	22.21
Sum	267.03	Sum	479.71
Count	44	Count	60

From the above table take .,mean,standard deviaton,sample size.

use confidence.t to get the margin of error

and

90% confidence interval as sample mean-margin of error,sample mean+margin of error

sample mean for breakfast is 6.068864

sample mean for lumch is 7.995167

to get the confidence intervals for breakfast in excel

margin of error

=CONFIDENCE.T(0.1;3.288743;44)

=0.833469243

sample mean=xbar	6.068864
margin of error	0.833469
90% lower limit of mean for breakfast	5.235394
90% upper limit of man for breakfast	6.902333

margin f error for 95%==CONFIDENCE.T(0.05;3.288743;44)=0.999869

sample mean=xbar	6.068864
margin of error	0.999869
95% lower limit of mean for breakfast	5.068994
95% upper limit of man for breakfast	7.068733

similarly 98% margin of error as

=CONFIDENCE.T(0.02;3.288743;44)

=1.197968748

sample mean=xbar	6.068864
margin of error	1.197969
98% lower limit of mean for breakfast	4.870895
98% upper limit of man for breakfast	7.266832