A brand of powdered milk is advertised as having a net weight of 250 grams. A curious consumer obtained the net weight of 10 randomly selected cans. The values obtained are: 245, 248, 242, 245, 246, 248, 250, 245, 243 and 249 grams. Is there reason to believe that the average net weight of the powdered milk cans is less than 250 grams at 5% level of significance? Assume the net weight is normally distributed with unknown population variance.
1. What is the appropriate null hypothesis?
A. The average net weight of the powdered milk cans is less than 250 grams.
B. The average net weight of the powdered milk cans is at most 250 grams.
C. The average net weight of the powdered milk cans is at least 250 grams.
D. The average net weight of the powdered milk cans is 250 grams.
2. What is the symbol for null hypothesis?
A. 0:<250g
B. 0:≤250g
C.0:≥250g
D.0:=250g
3. What will be the appropriate alternative hypothesis?
A. The average net weight of the powdered milk cans is less than 250 grams.
B. The average net weight of the powdered milk cans is at most 250 grams.
c. The average net weight of the powdered milk cans is at least 250 grams.
D. The average net weight of the powdered milk cans is greater than 250 grams.
4. What is the symbol for the alternative hypothesis?
A. 0:<250g
B. 0:≤250g
C.0:≥250g
D.0:≠250g
5. Identify the level of significance.
A. 5%
B. 0.5%
C. 0.10
6. What kind of test will be used?
A. One-tailed test
B. Two-tailed test
C. Three-tailed test
D. No-tailed test
Share
Answer:
1. B. The appropriate null hypothesis is "the average net weight of the powdered milk cans is at most 250 grams," which can be written as H0: μ ≥ 250g.
2. B. The symbol for the null hypothesis is H0: μ ≤ 250g.
3. D. The appropriate alternative hypothesis is "the average net weight of the powdered milk cans is greater than 250 grams," which can be written as Ha: μ > 250g.
4. D. The symbol for the alternative hypothesis is Ha: μ ≠ 250g.
5. A. The level of significance is 5%.
6. A. A one-tailed test will be used, because the alternative hypothesis is directional (i.e. it specifies a direction for the difference in means).