Type the correct answer in each box. Spell all words correctly, and use numerals instead of words for numbers. If necessary, use / for the fraction bar(s).
The scatter plot presents Ray's monthly electricity bills and the amount of time Ray spent at home from January through August.
Using the scatter plot, find the correlation coefficient of this data set.
The correlation coefficient (r) is
.
The correlation coefficient can be improved by ignoring the bill for the month of
