TABLE 9-3 An Appliance Manufacturer Claims to Have Developed a Compact Microwave

Multiple Choice

TABLE 9-3
An appliance manufacturer claims to have developed a compact microwave oven that consumes a mean of no more than 250 W.From previous studies,it is believed that power consumption for microwave ovens is normally distributed with a population standard deviation of 15 W.A consumer group has decided to try to discover if the claim appears true.They take a sample of 20 microwave ovens and find that they consume a mean of 257.3 W.
-Referring to Table 9-3,the appropriate hypotheses to determine if the manufacturer's claim appears reasonable are

A) H₀ : μ = 250 versus H₁ : μ ≠ 250.
B) H₀ : μ ≥ 250 versus H₁ : μ < 250.
C) H₀ : μ ≤ 250 versus H₁ : μ > 250.
D) H₀ : μ ≥ 257.3 versus H₁ : μ < 257.3.