1MA0 Higher June 2014 Paper 2 Q8
8 Lorna carries out a survey about the number of times customers go to a shop.
She asks at random 100 customers how many times they went to the shop last month.
The table shows Lorna’s results.
| Number of times | 0 | 1 | 2 | 3 | 4 | 5 | 6 | more than 6 |
|---|---|---|---|---|---|---|---|---|
| Frequency | 4 | 12 | 13 | 17 | 25 | 13 | 11 | 5 |
One of the 100 customers is chosen at random.
(a) What is the probability that this customer went to the shop 5 or more times? (2)
Last month the shop had a total of 1500 customers.
(b) Work out an estimate for the number of customers who went to the shop exactly 2 times last month. (2)
The owner of a different shop is carrying out a survey on the ages of his customers.
He records the ages of the first 10 customers in his shop after 9 am one morning.
(c) This may not be a suitable sample.
Give two reasons why. (2)
Give two reasons why. (2)
| Answer | Mark | Notes |
|---|---|---|
| \(\dfrac{29}{100}\) | 2 | M1 for 13 + 11 + 5 (=29) A1 for \(\dfrac{29}{100}\) oe (SC B1 for \(\dfrac{16}{100}\) oe) |
| Answer | Mark | Notes |
|---|---|---|
| 195 | 2 | M1 for \(1500 \times \dfrac{13}{100}\) oe A1 for 195 |
| Answer | Mark | Notes |
|---|---|---|
| reasons | 2 | B2 for 2 valid reasons eg sample too small, customers at this time may not be representative of ages of all customers (B1 for 1 reason) |