Share
Explore BrainMass

Stem and leaf plot and Hypothesis testing

Here is what I need help with. You can use any of the below information to get the answers. Please use the first set of results for the first one though.

I am in the military and I took a granade launcher and launched 30 rounds at a target and then measured how far from the target I was. Just so that you understand it is extremely hard to come within 3 meters of the target.
Results:
2.10
1.30
.16
1.06
1.48
1.56
2.19
4.46
4.36
1.63
3.17
5.00
5.20
.61
2.62
2.75
1.93
1.53
1.32
.25
3.31
1.45
2.32
1.12
4.58
2.29
3.95
4.42
1.89
2.67

The second test was with a bow an arrow from a very long distance away.
8.0
84
66
13
13
8
1.8
47
5.6
53
48.1
35.12
31.8
9.77
87.9
34.63
19.41
127.86
35.20
150.26
87.93
82.92
5.63
5.72
38.19
40.35
22.74
39.55
55.21
11.59

I randomly asked 30 people if they would perfer Bow and Arrow or a grenade

Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Bow and Arrow
Grenade
Bow and Arrow
Bow and Arrow
Grenade
Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Grenade
Grenade
Bow and Arrow
Bow and Arrow
Bow and Arrow
Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade

1. Describe the population that the data represents. From the data, plot a histogram and a stem-and-leaf diagram. Also calculate the mean, median, mode, range, standard deviation, and quartiles of the data. Explain what this analysis tells you.

Research Using the Web
Search the Web for real-life examples of hypothesis testing. Try searching for this information in Web-based articles, lectures, or tutorials. Write a few short paragraphs on what you retrieved.

Inferential Statistics

Perform each of the steps below using Excel. Describe the population that the data represents. Interpret each of your results with a conclusion and decision.

1. Develop a 90% confidence interval and a 95% confidence interval for the population mean. Did you use a z statistic or t statistics? Why? Compare the size and meaning of the two confidence intervals.

2. Test a hypothesis about a population mean. Take a random sample and perform a t-test against a population mean. Explain what assumptions you made.

3. Test a hypothesis comparing two population means. Collect two independent samples. Perform a t-test using two independent samples.

Solution Preview

Please see the attached solutions

Std dev. etc....
Here is what I need help with. You can use any of the below information to get the answers. Please use the first set of results for the first one though.

I am in the military and I took a granade launcher and launched 30 rounds at a target and then measured how far from the target I was. Just so that you understand it is extremely hard to come within 3 meters of the target.
Results:
2.10
1.30
.16
1.06
1.48
1.56
2.19
4.46
4.36
1.63
3.17
5.00
5.20
.61
2.62
2.75
1.93
1.53
1.32
.25
3.31
1.45
2.32
1.12
4.58
2.29
3.95
4.42
1.89
2.67

The second test was with a bow an arrow from a very long distance away.
8.0
84
66
13
13
8
1.8
47
5.6
53
48.1
35.12
31.8
9.77
87.9
34.63
19.41
127.86
35.20
150.26
87.93
82.92
5.63
5.72
38.19
40.35
22.74
39.55
55.21
11.59

I randomly asked 30 people if they would perfer Bow and Arrow or a grenade

Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Bow and Arrow
Grenade
Bow and Arrow
Bow and Arrow
Grenade
Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Bow and Arrow
Grenade
Grenade
Grenade
Grenade
Bow and Arrow
Bow and Arrow
Bow and Arrow
Grenade
Grenade
Grenade
Bow and Arrow
Grenade
Grenade

1. Describe the population that the data represents. From the data, plot a histogram and a stem-and-leaf diagram. Also calculate the mean, median, mode, range, standard deviation, and quartiles of the data. Explain what this analysis tells you.
Stem-and-Leaf Display
or Grenade
Stem unit: 1

0 2 3 6
1 1 1 3 3 5 5 5 6 6 9 9
2 1 2 3 3 6 7 8
3 2 3
4 0 4 4 5 6
5 0 2

The histogram and step and leaf suggests that the observations are normally distributed.

Stem-and-Leaf Display
for Bow and Arrow
Stem unit: 10

0 2 6 6 6 ...

Solution Summary

The solution provides step by step method for the calculation of stem and leaf plot.

$2.19