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
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