Patty’s Parasols recorded the monthly rainfall and their umbrella sales for an entire year. The following table shows the inches of rainfall and the number of umbrellas the store sold each month. The relationship between
the inches of rainfall and umbrella sales can be modeled using a linear function.
Month Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept. Oct. Nov. Dec.
Rainfall (in.) 2.5 3.1 4.0 4.3 3.6 2.4 1.2 0.6 1.5 1.4 1.1 2.6
Umbrella sales 132 140 162 170 156 103 98 87 84 78 110 125
(a) Using technology, determine the correlation coefficient for the data to the nearest hundredth. Explain
the steps you used.
(b) What does the correlation coefficient for the data indicate about the direction and strength of the
linear association between the monthly rainfall and the number of umbrellas sold?