3 A survey was conducted to find the proportion of people owning DVD players. It was found that 203 out of a random sample of 278 people owned a DVD player.
- Calculate a \(97 \%\) confidence interval for the true proportion of people who own a DVD player.
A second survey to find the proportion of people owning DVD players was conducted at 10 o'clock on a Thursday morning in a shopping centre.
- Give one reason why this is not a satisfactory sample.