Subjective Test Questions (Statistics)
Running head: SUBJECTIVE TEST QUESTIONS
Subjective Test Questions
Student Name
Institutional Affiliation
1
SUBJECTIVE TEST QUESTIONS
2
Q1
No, it is not reasonable to calculate a confidence interval for the data.
Reason: the population standard deviation is not given.
Q2
We are given:
Margin of estimate, e = 0.10(100) hours
Level of confidence, C.I = 95%
Standard deviation, ๐ = 0.90 hours
Sample size, n =?
๐งโ๐ 2
Sample size = (
๐
)
But at 95% level of confidence, z = 1.96 from tables
Hence,
1.96โ0.90 2
n=(
0.10
) = 311.1696
Therefore, the required sample size is 312.
Q3
We are given:
X=120
N=200
๐
120
Sample proportion, p=๐ = 200=0.6
๐(1โ๐)
Confidence interval of a population proportion = ๐ ยฑzโ
0.6(1โ0.6)
95% confidence interval = 0.6ยฑ1.96*โ
200
๐
SUBJECTIVE TEST QUESTIONS
3
95% confidence interval =0.6ยฑ0.0679
95% confidence interval = (0.5321, 0.6679)
Yes. The proportion of the Georgetown country residents who believe that countryโs real estate
taxes are too high is between 0.5321 and 0.6679 at 95% level of confidence.
Q4
First, state the null and alternative hypothesis
H0 : ๐0 = ๐1 = ๐2 (No significant difference in the mean selection sales)
H1 : ๐0 โ ๐1 โ ๐2 (Atleast one of the means of the selection sales is different)
Where;
๐0 = the mean for soft drink selection sales
๐1 = the mean for new registers sales
๐2 =the mean for dairy selection sales
To test where a significant difference exists, a one-way ANOVA model is conducted using MsExcel.
Anova: Single
Factor
SUMMARY
Groups
Column 1
Column 2
Column 3
ANOVA
Source of
Variation
Between
Groups
Within Groups
Count
5
5
5
SS
6.5333333
89.2
Sum
40
35
43
df
Average Variance
8
11.5
7
6.5
8.6
4.3
MS
2
12
F
P-value
F crit
3.2666667 0.439462 0.65435 3.885294
7.4333333
SUBJECTIVE TEST QUESTIONS
Total
95.733333
4
14
Decision rule at 5% significance level: Reject the null hypothesis if F> F critical (Kreyszig,
2010).
F=0.439
F critical = 3.885
Since F observed is less than F critical, we fail to reject the null hypothesis since we do not have
enough evidence. Therefore we conclude that there is no significant difference in the mean
selection of Coca-Cola stacked at four locations of the store.
SUBJECTIVE TEST QUESTIONS
5
Reference
Kreyszig, E. (2010). Advanced Engineering Mathematics, 10th Edition. John Wiley & Sons.
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