Question

Using the following to answer Q6-Q8: The results of inspection of DNA samples taken over the past 10 days are given below.

Sample size is 100.

Day 1 2 3 4 5 6 7 8 9 10
Defectives 7 6 6 9 5 6 0 8 9 1

What is the average defective rate for these samples?

Answer 1

The average defective rate of the samples is:

6.3 samples per day

Step-by-step explanation:

To calculate the average or mean defective rate, we will compute the total number of defective samples, and divide the result by the total number of days. It is important to note that day 7 is ignored during this calculation because there was no defective DNA sample on that day, hence it does not contribute to the average defective samples.

Total Defective DNA sample = 7 + 6 + 6 + 9 + 5 + 6 + 8 + 9 + 1 = 57

Total number of days = 9 ( Days 1 to 6, and 8 to 10).

Therefore, average defective rate = Total Defective DNA sample ÷ Total number of days

= 57 ÷ 9 = 6.3 DNA samples