Reference no: EM131066689
1. The following observations are the estimated payback periods (in years) for installation of aluminium-framed double glazing in a random sample of ten homes in Christchurch. These periods reflect the costs of installation, and energy savings from the insulation.
|
12.5
|
20.3
|
22.3
|
19.7
|
19.5
|
|
24.5
|
26.9
|
13.4
|
18.4
|
18.3
|
(a) Draw a boxplot of these data. Do you think a normality assumption is reasonable?
(b) Calculate a 95% confidence interval for the mean payback period for this sort of retro-fitted double glazing.
(c) How large a sample would be needed to estimate the mean payback period to within one year?
2. "The Great Morality Debate" - an online survey of New Zealanders asked "is it wrong for men and women to have sex before marriage?" A staggering 35% of the 9000 responses were "yes" although there were strong regional differences (only of 23% of respondents from Wellington answered in the affirmative).
(a) Calculate a 95% confidence interval for the population proportion who believe it is wrong to have sex before marriage.
(b) Assume that the sample data exclude Wellingtonians, and that the population proportion for Wellingtonians is p=23%. Is the sample proportion significantly higher?
3. The following table contains weighted average cost of capital estimates(WACC, in %) for a random sample of New Zealand firms in two sectors: consumer and property.
|
Consumer
|
|
11.0
|
7.0
|
8.1
|
9.4
|
10.8
|
7.0
|
11.3
|
7.6
|
|
9.1
|
6.8
|
7.4
|
8.3
|
12.7
|
8.7
|
7.3
|
|
|
Property
|
|
6.8
|
8.7
|
7.0
|
7.1
|
6.9
|
7.2
|
7.2
|
6.8
|
Assuming the WACCs are normally distributed with different variances, conduct a test of equality of means.
4. The following retail website brand awareness figures are the percentage of survey respondents who recognized the website brand:
|
Website
|
%2009
|
%2010
|
|
Farmers.co.nz
|
0.7
|
3.1
|
|
Thewarehouse.co.nz
|
4.2
|
12.7
|
|
Woolworths.co.nz
|
2.0
|
5.1
|
|
Harveynorman.co.nz
|
1.0
|
0.0
|
|
Dse.co.nz
|
3.9
|
6.0
|
|
Noelleeming.co.nz
|
3.4
|
4.8
|
|
1-day.co.nz
|
5.2
|
7.3
|
|
Ezibuy.co.nz
|
4.2
|
5.4
|
|
Mightyape.co.nz
|
1.7
|
1.9
|
|
Foodtown.co.nz
|
2.2
|
2.4
|
|
Smilecity.co.nz
|
3.9
|
4.1
|
|
Apple.com
|
2.0
|
2.1
|
(Answer a and b, but do the t-test in c anyway, ensuring that you reflect on whether or not it was a good idea to do so.)
(a) Why is a paired comparison justified for these two samples?
(b) Why is a t-test inappropriate for these two samples?
(c) Test the hypothesis that website brand recognition is increasing for retail websites generally.
|
Explanations of casimaty v fc of t 97 atc 5135
: HI6028 Taxation - Discuss whether Kit is a resident of Australia and how his salary and investment income would be taxed (10 marks, max. 1000 words).
|
|
State the null and alternative hypotheses
: The national mean SAT score in math is 550. Suppose a high school principal claims that the mean SAT score in math at his school is better than the national mean score. A random sample of 72 students finds a mean score of 574. Assume that the popu..
|
|
Use your own words and reporting phrases
: (2) Write a complete 1-paragraph summary of the article. Be sure to include all of the main ideas, but no unnecessary details or added information. USE YOUR OWN WORDS AND REPORTING PHRASES - Remind the reader these are not your ideas, only your w..
|
|
Find the constant of proportionality
: find the constant of proportionality.
|
|
Confidence interval for the mean payback period
: (a) Draw a boxplot of these data. Do you think a normality assumption is reasonable? (b) Calculate a 95% confidence interval for the mean payback period for this sort of retro-fitted double glazing. (c) How large a sample would be needed to estimate ..
|
|
Generate appropriate histograms or box plots
: Generate appropriate histograms or box plots. Find appropriate statistics that will help to understand the data set. Are there any notable features? Are there any outliers? Describe the key elements of center, variation, distribution, and outliers..
|
|
Where is the center of our universe
: What would the universe look like to an astronomer living in a galaxy several billion light years away? (Hint: explain why the universe would or would not look essentially the same as it would look to us).
|
|
Write a comparator class that compares products by price
: Write a comparator class that compares Products by price. Declare a priority queue that uses the comparator class in number 3 to compare Products.
|
|
Problem regarding the frequency distribution
: The following data set represents the amount spent (in dollars) by 45 shoppers at a supermarket. Construct a frequency distribution for the variable, and also report the relative frequencies for each class in your frequency distribution. NOTE: the..
|