Statistical Problems - Essay Example

The approximation becomes better with increasing sample size The simple random sample of 50 women with one job is greater than 30. Therefore, in this case Central Limit Theorem is applicable and the distribution of the sample can be assumed as normally distributed. (b) The percentage of all samples of 50 women with one job that have the mean length of time employed within 20 weeks of the population mean is (approximately) equal to the area under the normal curve with parameters µ and 13.01 that lies between µ - 20 and µ + 20.

The corresponding z-scores are: (c) No. If I bought one bag of water-softener salt and it weighed 39 lb, I would not consider this evidence that company’s claim is incorrect. Because there is 25.14% probability that the weight of one randomly selected bag of water softener salt will be 39lb or less. (d) Yes. If I bought 10 bag of water-softener salt and it mean weight was 39 lb, I would consider this evidence that company’s claim is incorrect. Because there is only 1.74% probability that the mean weight of 10 randomly selected bag of water softener salt will be 39lb or