the table shows the number of flowers in four bouquets and the total cost of each bouquet. what is the…

the table shows the number of flowers in four bouquets and the total cost of each bouquet. what is the correlation coefficient for the data in the table? cost of bouquets number of flowers in the bouquet total cost 8 $12 12 $40 6 $15 20 $20

the table shows the number of flowers in four bouquets and the total cost of each bouquet. what is the correlation coefficient for the data in the table? cost of bouquets number of flowers in the bouquet total cost 8 $12 12 $40 6 $15 20 $20

Answer

Explanation:

Step1: Calculate the means

Let (x) be the number of flowers and (y) be the total cost. (\bar{x}=\frac{8 + 12+6+20}{4}=\frac{46}{4} = 11.5) (\bar{y}=\frac{12 + 40+15+20}{4}=\frac{87}{4}=21.75)

Step2: Calculate the numerator of the correlation - coefficient formula

(n = 4) (\sum_{i = 1}^{n}(x_{i}-\bar{x})(y_{i}-\bar{y})=(8 - 11.5)(12-21.75)+(12 - 11.5)(40 - 21.75)+(6 - 11.5)(15 - 21.75)+(20 - 11.5)(20 - 21.75)) (=(-3.5)(-9.75)+(0.5)(18.25)+(-5.5)(-6.75)+(8.5)(-1.75)) (=34.125 + 9.125+37.125-14.875) (=65.5)

Step3: Calculate the denominator of the correlation - coefficient formula

(\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}=(8 - 11.5)^{2}+(12 - 11.5)^{2}+(6 - 11.5)^{2}+(20 - 11.5)^{2}) (=(-3.5)^{2}+(0.5)^{2}+(-5.5)^{2}+(8.5)^{2}) (=12.25 + 0.25+30.25+72.25) (=115) (\sum_{i = 1}^{n}(y_{i}-\bar{y})^{2}=(12 - 21.75)^{2}+(40 - 21.75)^{2}+(15 - 21.75)^{2}+(20 - 21.75)^{2}) (=(-9.75)^{2}+(18.25)^{2}+(-6.75)^{2}+(-1.75)^{2}) (=95.0625+333.0625 + 45.5625+3.0625) (=476.75) (\sqrt{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}\sum_{i = 1}^{n}(y_{i}-\bar{y})^{2}}=\sqrt{115\times476.75}=\sqrt{54826.25}\approx234.15)

Step4: Calculate the correlation coefficient (r)

(r=\frac{\sum_{i = 1}^{n}(x_{i}-\bar{x})(y_{i}-\bar{y})}{\sqrt{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}\sum_{i = 1}^{n}(y_{i}-\bar{y})^{2}}}=\frac{65.5}{234.15}\approx0.28)

Answer:

0.28