The county health department has concerns about the chlorine
The county health department has concerns about the chlorine level at a local water park.
Suppose the proportion of the water readings on Monday is Pm and the proportion of the water
readings on Thursday is Pt. A study found a 90% confidence interval for Pm- Pt is (-0.05, 0.04). Give an interpretation of this confidence interval.
A) We are 90% confident that the chlorine level on Thursday is between 5% less and 4% more than the chlorine level on Monday.
B) If samples were repeatedly drawn from the same populations under the same
circumstances, the true population difference ( Pm- Pt ) would be between -0.05 and 0.04
90% of the time.
C) The probability that the chlorine level on Thursday is between 5% less and 4% more than
the chlorine level on Thursday is 90%.
D) We are 90% confident that the chlorine level on Monday is between 5% less and 4% more
than the chlorine level on Thursday.
E) The probability that the chlorine level on Monday is between 5% less and 4% more than the
chlorine level on Thursday is 90%.
Solution

