Complete Question
Martin is conducting an experiment. His first test gives him a yield of 5.2 grams. His second test gives him a yield of 1.3 grams. His third test gives him a yield of 8.5 grams. On average, his yield is 5.0 grams, which is close to the known yield of 5.1 grams of substance. Which of the following are true?
A His results are accurate but not precise.
B His results are neither accurate nor precise.
C His results are both accurate and precise
D His results are precise but not accurate.
Answer:
Correct option is A
Explanation:
From the question we are told that
The yield of the first test 
The yield of the second is 
The third yield is 
The average yield 
The know yield is 
From the data given we see that

Since his average yield is closer to the known yield then the answer is accurate
But since the yield for each test are not repeated the answer is not precise
So the answer is accurate but not precise