In a random sample of 400 watches, three are defective. Out of the total of 10,500 watches how many would you expect to be defective based on the sample data?

Answer 1

To calculate the expected number of defective watches in the total population of 10,500 watches based on the sample data, we can use the proportion of defective watches in the sample.

In the sample of 400 watches, 3 are defective. Therefore, the proportion of defective watches in the sample is 3/400 = 0.0075.

To find the expected number of defective watches in the total population of 10,500 watches, we multiply the proportion of defective watches in the sample by the total number of watches in the population:

0.0075 * 10,500 = 78.75

Therefore, based on the sample data, you would expect approximately 78.75 watches out of the total 10,500 watches to be defective. Since you can't have a fraction of a watch, you would round this to the nearest whole number. So, you would expect approximately 79 watches to be defective in the total population.