s. You are a consulting engineer trying to improve the water quality from stormw

Question

s. You are a consulting engineer trying to improve the water quality from stormwater runoff at your commercial site. Specifically, you are trying to reduce the total suspended solids (TSS) in rainwater runoff reaching the adjacent stream. Prior to the study, average TSS concentrations were 200 mg/L. After installing upstream improvements, the TSS concentrations are now 190 mg/L with a standard deviation = 35 mg/L. Assume n 33 tests. Determine Ho, Hi, and the p-value. Is Ho plausible or is it rejected?

Explanation / Answer

H0 : = 200 mg/L

Ha : < 200 mg/L

Here x = 190 mg/L

s = 35 mg/L

n = 33 tests

Here test statistic

t = (x- 200)/ (s/ sqrt(n)

t = (190 - 200)/ (35/ sqrt(33)

t = -10/ 6.093 = -1.64

p- value = Pr(t < -1.64; 32; 0.05) = 0.0554

so yes p - value > 0.05 so null hypothesis is plausible and there is no decrease in TSS concentrations.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

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