- The 4 Point Data Set Below Has A Mean Equal To 4 2 X 3 5 Find A The Value Of X 2 Marks B The Variance Give You 1 (66.9 KiB) Viewed 12 times
A discrete random variable X has the probability density function p(x) = Prob(X=x), as given in the following, incomplete, table. X p(x) 1 0.15 2 0.25 4 0.25 a) Calculate p(16) b) Find the expected value, E(X) c) Find the variance, Var(X) (2 marks) (1 mark) (2 marks) 8 0.20 16
A researcher involved in market research for a new cosmetic line wanted to run a focus group of potential female users. As the product is targeted to working females, the researcher decided to include females who are 21 years to 55 years of age. He selected 800 females who are within this age group across the country and planned to run several focus group sessions. a) Using the above extract i) define sample and sampling frame (2 marks) ii) in the context of this research describe the sample and sampling frame (2 marks) b) The researcher wants to undertake stratified random sampling. Explain how this can be done (3 marks) c) Explain two ways of collecting data for research (3 marks)