For Exercises 2.23 and 2.24, see page 75; and for 2.25 and 2.26, see pages 77–78.

Question 2.30

2.30 Use a log for the radioactive decay

Refer to the previous exercise and to Exercise 2.18 (page 73), where you transformed the counts with a logarithm.

decay

  1. Is the relationship between time and the log of the counts strong? Explain your answer.
  2. Find the correlation between time and the log of the counts.
  3. Do you think that the correlation you computed gives a good numerical summary of the strength of the relationship between these two variables? Explain your answer.
  4. Compare your results here with those you found in the previous exercise. Was the correlation useful in explaining the relationship before the transformation? After? Explain your answers.
  5. Using your answer in part (d), write a short explanation of what these analyses show about the use of a correlation to explain the strength of a relationship.