1.1. A toy shop, 'Toys 4 U', tests the battery life for a new toy by leaving a sample of the toys switched on until their batteries run out.

Give one reason why the shop decided to use a sample rather than a census.

1.2. Five toys out of a shipment of 5000 were tested and the battery life (in minutes) of each toy was recorded:

172 minutes      252 minutes       248 minutes        155 minutes        161 minutes

The shop decides to display a sign beside the toys saying 'Up to 4 hours battery life'.
Use the sample data above to comment on the sign.

1.3. Suggest one way in which the shop could improve its prediction.