Statistics Homework Help

1)Two separate marketing teams, Team A and Team B, have each designed a 30 second advertisement for the new Cloak

soft drink. The manager of marketing is interested to see if there is any difference between the effectiveness of the two ads.

A random sample of 50 people are shown the ad from Team A and asked if they would definitely buy the new drink. In this sample, 18 people said that they would. A second random sample of 50 people are shown the ad from Team B and asked if they would definitely buy the drink. In this sample, 14 people said that they would.

Let 1 denote the population proportion of people that would definitely buy the drink if they saw the ad from Team A. Let 2 denote the population proportion of people that would definitely buy the drink if they saw the ad from Team B.

A hypothesis test is conducted with the following hypotheses:

H0: 1 = 2

HA: 1 ≠ 2

The level of significance used in this test is 0.05. You may find this standard normal table useful.

a)Calculate the test statistic (z) for this test. Give your answer to 2 decimal places.

z =  i believe it is 8.57

b)In this test the null hypothesis 

not sure how to tell is i should reject or not.. Which table do i use?

2)

Due to various socio-economic factors, residents of a particular city have an unusually high level of attendance at private schools. A study is conducted to determine whether there is any difference between the rate at which males and females choose private schools over public schools in this city.

A random sample of 84 males from the city are contacted and asked if they attend or ever attended a private school. The number that did is 44. Similarly, a random sample of 140 females from the city are contacted and asked the same question. The number that attended a private school is 53.

Let 1 denote the population proportion of males that attended a private school. Similarly, let 2 denote the population proportion of females that attended a private school.

Construct a 90% confidence interval for the difference between these two proportions (1 – 2). Give your answers to 3 decimal places. You may find this standard normal table useful.

_ ≤ 1 – 2 ≤ _