A company manufactures 2,000 units of its flagship product in a day. The quality control department takes a random sample of 40 units to test for quality. The product is put through a wear-and-tear test to determine the number of days it could last. If the product has a lifespan of less than 26 days, it is considered defective. The table gives the sample data that a quality control manager collected.

39 31 38 40 29
32 33 39 35 32
32 27 30 31 27
30 29 34 36 25
30 32 38 35 40
29 32 31 26 26
32 26 30 40 32
39 37 25 29 34

Question

A company manufactures 2,000 units of its flagship product in a day. The quality control department takes a random sample of 40 units to test for quality. The product is put through a wear-and-tear test to determine the number of days it could last. If the product has a lifespan of less than 26 days, it is considered defective. The table gives the sample data that a quality control manager collected. 

39	31	38	40	29
32	33	39	35	32
32	27	30	31	27
30	29	34	36	25
30	32	38	35	40
29	32	31	26	26
32	26	30	40	32
39	37	25	29	34

xenesis98 · Answer

Which statement is true about the population proportion of defective pieces in the 2,000 items?
a. 5 pieces must be defective.
b. 100 pieces must be defective.
c. More than 100 pieces must be defective.
d. The population proportion of defective pieces must be equal to the sample proportion.
e. There is insufficient data to calculate the proportion of defective pieces.