My Notes Ask Your leäche 6. 0-9 points BBUnderStat11 8 R008 ty respect except th

Question

My Notes Ask Your leäche 6. 0-9 points BBUnderStat11 8 R008 ty respect except that one is orange and the other is yellow. The orange paint is applied to 13 bridges, and the yellow paint is applied to 13 bridges. After a period of I year, reflectometer readings were made on all these bridge end pillars. (A higher readin means better visibility.) For the orange paint, the mean reflectometer reading was x1 highway department is testing two types of reflecting paint for concrete bridge end pllars. The two kinds of paint are alike in 9.4, with standard devlation s 2.5. For the yellow paint the mean was & 7.0, with standard deviation s - 1.6. Based on these data, can we conclude that the yelow paint has less visibility after 1 year? Use a 5% level of significance. What are we testing in this problem? O difference of means O single proportion O difference of proportions O paired difference O single mean a) What is the level of significance? State the null and alternate hypotheses. (b) What sampling distribution will you use? What assumptions are you making? O The Student's t. we assume that both population distributions are approximately normal with known standard deviations O The Student's t. We assume that both population distributions are approximately normal with unknown standard O The standard normal. we assume that both population distributions are approximately normal with known standard O The standard normal. We assume that both population distributions are approximately normal with unknown standard deviations de deviations. deviations what is the value of the sample test statistic? (Test the difference#1-P2, Round your answer to three decimal places.)

Explanation / Answer

difference of means

a)
0.05 level of significance.

H0 : mu1 = mu2; Ha : mu1 <mu2

b)
Option B.

test statistics:
n1 = n2 = 13, x1 = 9.4 ,s1 = 2.5 , x2 = 7 , s2 = 1.6

t = (x1 - x2) / sqrt(s1^2/n1 + s2^2/n2)
= (9.4 - 7) / sqrt(2.5^2/13 + 1.6^2/13)
= 2.915

d)
p value = .0038

sampling distribution of area corresponding to p value graph is option B)

at alph 0.05 leve; we reject the null hypothesis and conclude data are statistically significant.

e)
There is sufficinet evidence at the 0.05 level thata the yellow paint has less visibility after 1 year

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---

---

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