In a random sample of 30 Local Authorities, 12 had an increase of more than 2 percentage points in the proportion working mainly at or from home between 2001 and 2011. In an independent random sample of 80 Local Authorities, 28 had such an increase.
Calculate the two sample proportions.
Use each sample separately to estimate the number, out of 348, with such an increase.
Calculate the estimate obtained by combining the two samples.
Explain why none of the three estimates should be presented as an exact population count.