Homework Answers

5. A teacher wants to test his assumption that less than 30% of the Senior High

School students liked research class. After randomly collecting 150 samples,

he found out that only 40 students like their research class.

Claim:

Parameter

Symbol for parameter

Ho and Ha complementary pair.

Hypotheses in words:

Ho

Ha:

Hypotheses in symbols

Ho

На:

3. The Senior High School researchers claim that more than 20% of Senior High

School male students have tried smoking cigarette. After collecting 150 random

samples, they found that 60 of them have tried smoking cigarette.

Claim:

Parameter

Symbol for parameter

Ho and Ha complementary pair.

Hypotheses in words:

Ho

Ha:

Hypotheses in symbols

Ho

На:

4. In a certain town a school principal hypothesized that students enroll in schools

within 5 km from their homes. To check this claim you ask 38 students from

the said town. You found out that the average distance between the students

home and their schools is 5.6 km.

Claim:

Parameter

Symbol for parameter

Ho and Ha complementary pair.

Hypotheses in words:

Ho

Ha:

Hypotheses in symbols

Ho

На:

What is the probability that, for the sample of 115 customers, the proportion who wait longer than five days for their order to be delivered is less than 13.75%? Interpret your answer

A shop owner claims that on average, his shop has a daily turnover of R75 000. Test this claim at the 5% significance level, if the average daily turnover for a sample of 88 days was R71 500. Assume a population standard deviation of R4 450.

The CEO of Global Investment Funds claims that, on average, clients leave their investment funds with the company for a period of at least 56 months. Test this claim at the 10% significance level, if it was found that a sample of 29 clients left their investment funds with the company for an average period of 58.85 months, with a standard deviation of 3.75 months

A large manufacturing company claims that more than 88% of its customers are fully satisfied with the company’s products. Test this claim at the 5% significance level, if a survey found that 360 out of a random sample of 400 of the company’s customers said that they were fully satisfied with the company’s products.

Given the following information, construct the rejection region. Show the solution in

a step-by-step procedure.

H 0 : = 45

H a : < 45

= 40, = 12, n = 32, = 0.01

Decompose (x^2+x+1)/((x+3)(x^2-x+1))

Show that every group of order 5*7*47 is abelian and cyclic.