a) The standard deviation of the purchases of consumers at a particular store is

Question

a) The standard deviation of the purchases of consumers at a particular store is $18. In a population of 500, a random sample of 100 customers is selected. i) What is the standard error of the sampling distribution?(3 marks) ii) What is the probability the sample mean exceeds the population mean by more than $5? 4 marks) b) The County, a weekly Kenyan publication, measured the mean interest rates of 9 counties located west of Rift valley and 15 counties located to the east. The values were reported as: Counties location Sample mean Sample standard deviation West 14.4% 2.3% East 11.2% 1.8% Calculate a 95% confidence interval for the difference between the mean interest rates s in all 4 ma

Explanation / Answer

a i. Here sd=18

So standard error=sd/sqrt(n)=18/10=1.8

ii Here we need to find P(z>5/1.8)=P(z>2.78)=0.0027

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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