Question

1. Facebook penetration values (the percentage of a country’s population that are Facebook users) for 15 randomly selected countries are: 52.56, 33.09, 5.37, 19.41, 32.52, 41.69, 51.61, 30.12, 39.07, 30.62, 38.16, 49.35, 27.13, 53.45, 40.01.
   1. Give point estimates for the population mean Facebook penetration (µ), and the population standard deviation of Facebook penetration (_σ).
   2. Construct a 95% confidence interval estimation for µ. Interpret.
   3. Construct a 95% confidence interval estimation for _σ. Interpret.
   4. What assumptions do you need to make about the population so that the

confidence intervals given in (b) and (c) are valid?

Answer 1

d. The assumptions needed to construct this confidence intervals are

1. The selected samples should be randomly and independently selected.

2. The samples should be approximately normally distributed.