Step 1

Given:

Confidence level = 0.90

Z for 90% confidence level = 1.645 …using z-table

Margin of error = E = 0.05

Step 2

Proportion of women = 0.5 …As it is not given, it can be assumed to be 0.5

We have to find minimum sample size.

Formula:

\(\displaystyle{n}=\hat{{{p}}}\times{\left({1}-\hat{{{p}}}\right)}\times{\left(\frac{{z}}{{E}}\right)}^{{2}}\)

Step 3

Using all values,

\(\displaystyle{n}={0.5}\times{0.5}\times{\left(\frac{{1.645}}{{0.05}}\right)}^{{2}}\approx{271}\)

Minimum sample size is 271

Given:

Confidence level = 0.90

Z for 90% confidence level = 1.645 …using z-table

Margin of error = E = 0.05

Step 2

Proportion of women = 0.5 …As it is not given, it can be assumed to be 0.5

We have to find minimum sample size.

Formula:

\(\displaystyle{n}=\hat{{{p}}}\times{\left({1}-\hat{{{p}}}\right)}\times{\left(\frac{{z}}{{E}}\right)}^{{2}}\)

Step 3

Using all values,

\(\displaystyle{n}={0.5}\times{0.5}\times{\left(\frac{{1.645}}{{0.05}}\right)}^{{2}}\approx{271}\)

Minimum sample size is 271