A consumer research organization was interested in the influence of type of wate

Question

A consumer research organization was interested in the influence of type of water on the effectiveness of a detergent. Test batches of washings were run in four randomly chosen machines having a particular type of water - soft, moderate, and hard. All batches had equal numbers of oil-stained rags and after each washing the number of rags stilled stained was determined. The following results were obtained.

Number of Rags with Stains

Sample Observations -------Soft --------Moderate ---------Hard

1 0 4 10

2 1 8 5

3 2 3 7

4 1 5 10

Using an alpha level of .01, would you conclude that the type of water influences the effectiveness of the detergent? (Please use excel)

Explanation / Answer

Null Hypothesis (H0): The type of water does not influences the effectiveness of the detergent

Alternative Hypothesis (H1): The type of water influences the effectiveness of the detergent

For the given data Anova single factor in data analysis (using excel) out put is

Decision rule: F caluculated value > F critical value

i.e 13.05882 > 8.021517

Therefore, Reject H0

Conclusion: At alpha = 0.01 L.O.S, the type of water influences the effectiveness of the detergent

  

Anova: Single Factor SUMMARY Groups Count Sum Average Variance Soft 4 4 1 0.666667 Moderate 4 20 5 4.666667 Hard 4 32 8 6 ANOVA Source of Variation SS df MS F P-value F crit Between Groups 98.6666667 2 49.33333 13.05882 0.002184 8.021517 Within Groups 34 9 3.777778 Total 132.666667 11

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.