When testing gas pumps for accuracy, fuel-quality enforcement specialists tested

Question

When testing gas pumps for accuracy, fuel-quality enforcement specialists tested pumps and found that 1266 of them were not pumping accurately (within 3.3 or when 5 gal is pumped), and 5689 pumps were Use a 0.01 significance level to test the claim of an industry representation that less than 20% of the pumps are inaccurate. Use the P-value method and use the normal distribution as an approximation to the distribution. Identify the null hypothesis and alternative hypothesis. A. H_0: p = 0.2 H_1: p > 0.2 B. H_0: p > 0.2 H_1: p = 0.2 C. H_0: p

Explanation / Answer

Solution:

Total number= 5680+1266 = 6946
a) Test Hypothesis:
F) HO: p = 0.2
H1: p < 0.2

(b) The test statistic is

Z = (phat-p)/sqrt(p*(1-p)/n)

= (1266/6946-0.2)/sqrt(0.2*0.8/6946)

= -3.69

(c) It is a left-tailed test.

So the p-value = P(Z<-3.69) =0.0002 (from standard normal table)

(d) Because the P-value is 0.0002 the significance level, 0.01 the null hypothesis. There is sufficient evidence support the claim that less than 20% of the pumps are inaccurate.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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