Statistics Solutions
Applied Statistics Solutions
1. Define Hypothesis testing...
1. Define Hypothesis testing and explain briefly the five standard steps involved in this process. 2. The long-distance calls made by the employees of a company are normally distributed with a mean of...
1. Define Hypothesis testing and explain briefly the five standard steps involved in this process.
2. The long-distance calls made by the employees of a company are normally distributed with a mean of 6.3 minutes and a standard deviation of 2.2 minutes.
Find the probability that a call:
2.1. Lasts between 5 and 10 minutes.
2.2. Lasts more than 7 minutes.
2.3. Lasts less than 4 minutes
3. A manufacturer of light bulbs advertises that, on average, its long-life bulb will last more than 5 000 hours. To test the claim, a statistician took a random sample of
100 bulbs and measured the amount of time each bulb burned out. She found that the sample mean was 5065 hours. If we assume that the lifetime of this type of bulb is normally distributed and has a standard deviation of 400 hours, test at 5% level of
significance the manufacture's claim is true.
The General Manager of a chain of furniture stores believes that experience is the most important factor in determining the level of success of a salesperson. To examine this belief she records last month's sales (in R1 000s) and the years of experience of 10 randomly selected salespeople. These data are listed in the table below:
Identify the independent and the dependent variables.
Construct a scatter plot to portray the data in table 2.
Calculate the coefficient of correlation.
Interpret your findings in (2.3) above.
Use the least-square method to determine the regression equation.
Explain what the coefficients (the slope and the intercept) of the equation in (2.5) tell you about the relationship between years of experience and monthly sales
XXXXXXXXXXEstimate the monthly sales for a salesperson with 16 years of experience.
The prices and per capita consumption of four (4) basic food items for the years 2005 and 2011 are displayed in tablebelow:
Table.
Prices (R / kg)
1.1 W ith 2005 as base year, calculate for the year 2011 the Laspeyres price and quantity indices and interpret your answers
1.2 The following data refer to the number of visitors (in thousands) that visited the uShaka water world in the years XXXXXXXXXX.
Jan-Apr
May-Aug
Sep-Dec
You are required to:
1.2.1 Obtain a 3-term moving average trend.
1.2.2 Find the seasonal variations using the additive model.
Microsoft Word - ECON2016 Unit 4 and 5 Practice Questions.docx1Units4and5AdditionalPracticeQuestionsFind additional practice questions for Units 4 and 5 in preparation for the graded...
Suppose that 20 of the parts manufactured by the processes in Exercise 8.9 were assembled so that their dimensions were additive; that is,x =x1 + x2 XXXXXXXXXXx20Specifications on x are 2000 ±200. Would...
The service life of a battery used in a cardiac pacemaker is assumed to be normally distributed. A random sample of 10 batteries is subjected to an accelerated life test by running them continuously...
COUN 503Web Calculator Exercise 4Non-parametric tests (Chi-square tests, Wilcoxon-rank-sum & Wilcoxon signed-ranks tests)Note: When searching for a web calculator for the Wilcoxon-rank-sum test,...
Portfolio of Statistical ExercisesFor this portfolio of statistical exercises you will be presented with FIVE research questions and datasets which you need to conduct the relevant statistical test(s)...
25. The College Board reported the following mean scores for the three parts of the Scholas- tic Aptitude Test (SAT) (The World Almanac, 2009):Critical Reading502Mathematics515Writing494Assume that...
The invasive diatom species Didymosphenia geminata has the potential to inflict substantial ecological and economic damage in rivers. The article "Substrate Characteristics Affect Colonization by the...
This assignment focuses on computing new variables, measures of central tendency and dispersion, and basic distributional analyses. A secondary focus will be on presenting this information through...
Exercise instructions 2.2 FEMPrerequisite: Slides XXXXXXXXXX(1) Implement the Finite Element Modeling heat transfer model shown on slides XXXXXXXXXXWhen programming the cell formulas, be...
More specifically, you will XXXXXXXXXXresearch and/or calculate one morbidity rate (e.g. incidence or prevalence XXXXXXXXXXHIV Mortality Morbidity and Prevalence in Haiti...