A student measured the data in the tables below by recording the time, t; it took two different cylinders (one solid and one hollow) with the same dimensions to roll, from rest, down a slope for a fixed distance.
Theory suggests that the hollow cylinder should take longer to travel the same distance as the solid cylinder.
Solution:
Part A)
Frequencies
Statistics
Rolling time for hollow cylinder/sec
Rolling time for solid cylinder/sec
Rolling time for hollow cylinder/sec (Binned)
Rolling time for solid cylinder/sec (Binned)
N
Valid
45
45
45
45
Missing
0
0
0
0
Mean
2.0529
1.8049
4.00
3.84
Std. Deviation
.04586
.06247
.000
.796
Frequency Distribution
Rolling time for hollow cylinder/sec
Frequency
Percent
Valid Percent
Cumulative Percent
Valid
1.97
2
4.4
4.4
4.4
1.98
1
2.2
2.2
6.7
1.99
2
4.4
4.4
11.1
2
2
4.4
4.4
15.6
2.01
3
6.7
6.7
22.2
2.02
3
6.7
6.7
28.9
2.03
5
11.1
11.1
40.0
2.04
2
4.4
4.4
44.4
2.05
3
6.7
6.7
51.1
2.06
3
6.7
6.7
57.8
2.07
6
13.3
13.3
71.1
2.08
3
6.7
6.7
77.8
2.1
3
6.7
6.7
84.4
2.11
2
4.4
4.4
88.9
2.12
3
6.7
6.7
95.6
2.13
1
2.2
2.2
97.8
2.16
1
2.2
2.2
100.0
Total
45
100.0
100.0
Rolling time for solid cylinder/sec
Frequency
Percent
Valid Percent
Cumulative Percent
Valid
1.62
1
2.2
2.2
2.2
1.67
1
2.2
2.2
4.4
1.72
1
2.2
2.2
6.7
1.73
2
4.4
4.4
11.1
1.74
2
4.4
4.4
15.6
1.76
2
4.4
4.4
20.0
1.77
5
11.1
11.1
31.1
1.78
2
4.4
4.4
35.6
1.79
4
8.9
8.9
44.4
1.8
3
6.7
6.7
51.1
1.81
4
8.9
8.9
60.0
1.82
2
4.4
4.4
64.4
1.83
1
2.2
2.2
66.7
1.84
4
8.9
8.9
75.6
1.85
1
2.2
2.2
77.8
1.86
1
2.2
2.2
80.0
1.87
4
8.9
8.9
88.9
1.88
1
2.2
2.2
91.1
1.89
1
2.2
2.2
93.3
1.9
2
4.4
4.4
97.8
1.95
1
2.2
2.2
100.0
Total
45
100.0
100.0
Rolling time for hollow cylinder/sec (Binned)
Frequency
Percent
Valid Percent
Cumulative Percent
Valid
1.95 - 2.16
45
100.0
100.0
100.0
Rolling time for solid cylinder/sec (Binned)
Frequency
Percent
Valid Percent
Cumulative Percent
Valid
1.61 - 1.69
2
4.4
4.4
4.4
1.70 - 1.77
12
26.7
26.7
31.1
1.78 - 1.86
22
48.9
48.9
80.0
1.87+
9
20.0
20.0
100.0
Total
45
100.0
100.0
Part B)
Histogram
Part D)
Standard Deviation of Rolling time for Hollow cylinder
0.05
Standard Deviation of Rolling time for Solid cylinder
0.06
Part E)
Compare Means
Ho: Hollow cylinder should not take longer to travel the same distance as the solid cylinder.
H1: Hollow cylinder should take longer to travel the same distance as the solid cylinder.
The methodology used to test this hypothesis is one-sample T test at the 95% level of confidence.
The test results are as follows;
One-Sample Statistics
N
Mean
Std. Deviation
Std. Error Mean
Rolling time for hollow cylinder/sec
45
2.0529
.04586
.00684
Rolling time for solid cylinder/sec
45
1.8049
.06247
.00931
One-Sample Test
Test Value = 0
t
df
Sig. (2-tailed)
Mean Difference
95% Confidence Interval of the Difference
Lower
Upper
Rolling time for hollow cylinder/sec
300.310
44
.000
2.05289
2.0391
2.0667
Rolling time for solid cylinder/sec
193.806
44
.000
1.80489
1.7861
1.8237
Interpretations
The means of both the samples are different and the significant value of the test is less than the 5% level of significance. Therefore the null hypothesis is rejected.
It is concluded that Hollow cylinder should take longer to travel the same distance as the solid cylinder.
Task 2: (20 marks)
Use the “SDF results data” excel file to answer this question.
The data file shows the module results for 100 SDF students and includes the intended degree route of the students, marks gained in each module and an overall attendance figure; all data in the table is given as percentages.
The following criteria are applied to find the overall grade for the course: Grade
Criteria
Pass with Distinction
Pass all modules with = 40% and gain a mean mark of = 70% across all modules