A factory makes memory cards in batches of 4000. For testing purposes, 150 memory cards are selected at random from each batch. Of this sample, 9 memory cards are found to be broken. About how many memory cards in the batch are likely to be broken in all?

Question

( 16,667
В 240
444.
0 10

Answer 1

To estimate the total number of broken memory cards in the entire batch of 4000 cards based on the sample of 150 cards, we can use the proportion of broken cards in the sample.

1. Calculate the proportion of broken cards in the sample:

   • Number of broken cards in sample: 9
   • Total number of cards in sample: 150

   Proportion of broken cards = \( \frac{9}{150} = 0.06 \)

2. Estimate the total number of broken cards in the entire batch:

   • Total number of cards in batch: 4000

   Estimated number of broken cards = Proportion of broken cards × Total number of cards in batch \[ \text{Estimated number of broken cards} = 0.06 \times 4000 = 240 \]

Therefore, the likely number of broken memory cards in the batch is 240.

So the answer is 240.