The manager of a sawmill wants to find out what percentage of the boards that the mill produced are defective. Which sampling methods are likely to be biased? Select each correct answer.

A.Every 40th board produced over the course of 1 week is selected and examined.

B. On 1 day, an hour after the sawmill begins production, 30 boards in a row are selected and examined.

C. The manager selects 20 boards at random each day for 5 days and examines them.

D. The manager sends an email to 20 customers who buy lumber from the mill, asking each how many of the boards they bought the past week were defective. Results from the first 5 customers to respond are tallied.

Sampling is the choosing of a group of individuals from within a statistical population to estimate attributes of the entire population. Options C & D are right.

What is the sampling method ?

Sampling is the choosing of a group of individuals from within a statistical population to estimate attributes of the entire population in statistics, quality assurance, and survey methods.

The following options are right;

C. The manager selects 20 boards at random each day for 5 days and examines them.

Reason;

This method, which involves sampling 30 boards in a row an hour after manufacturing begins, does not yield a significant sample size.

Furthermore, if a component of the equipment fails later in the day, the statistics will be deceptive. Similarly, statistics will be deceptive if the gear is only defective until it "warms up."

D. The manager sends an email to 20 customers who buy lumber from the mill, asking each how many of the boards they bought the past week was defective. Results from the first 5 customers to respond are tallied.

Reason;

These technique, a voluntary survey, is likely to elicit replies solely from those who have strong feelings about their product.

Hence Options C & D are right.

To learn more about the sampling method refer to the link;

https://brainly.com/question/15125943