Assume that the sample mean is close to the population mean, and estimate the total and other values for the entire population.
📘 Example ①
Of the 5000 products produced at a factory in one day, 100 were selected and weighed. Their mean weight was 52g. Estimate the total weight of all the products.
Answer:Population mean ≈ sample mean = 52g. Total = 5000 × 52 = 260000g（260kg）
Of the 5000 products produced at a factory in one day, 100 were selected and weighed. Their mean weight was 52g. Estimate the total weight of all the products.
Answer:Population mean ≈ sample mean = 52g. Total = 5000 × 52 = 260000g（260kg）
💡 Key Point
- Population mean ≈ sample mean (estimated value)
- Total = population size × estimated mean
Practice Problem
- Forty bags were selected from 2000 bags of snacks and weighed. Their mean weight was 105g. Estimate the total weight of all the bags.
Answer and Explanation
- Answer:210000g（210kg）. 2000×105=210000.