Question

23 60 95 140 150 173 12 (a) Make a scatter diagram of the data and visualize the line you think best fits the data Tools Clear All Fill 110 Ic0 No 1D12141 1820222426 Object Properties Select a Tool or Object to Begin Help WabAssign. graphing tool Submission Data (b) Would you say the correlation is low, moderate, or strong? O low moderate strong Would you say the correlation is positive or negative? positive O negative y x2-914, y y-618, y y2-84554, and y xy-8,509 (c) Use a calculator to verify that 58, x Compute r. (Round your answer to three decimal places.) As x increases from 3 to 23 months, does the value of r imply that y should tend to increase or decrease? Explain your answer. O Given our value of r, y should tend to decrease as x increases O Given our value of r, y should tend to remain constant as x increases

Answer 1

	X	Y	X * Y	$X^2$	$Y^2$
	3	60	180	9	3600
	6	95	570	36	9025
	12	140	1680	144	19600
	14	150	2100	196	22500
	23	173	3979	529	29929
Total	58	618	8509	914	84654

Scatter Plot 200 180 160 140 120 100 80 60 40 20 0 舟 … 10 20 15 25

Part b)

O strong

Would you say the correlation is positive or negative? positive

$r = ( ( N * \Sigma XY) - \Sigma X \Sigma Y) / (\sqrt{ (N \Sigma (X^{2}) - (\Sigma X)^{2} )(N \Sigma (Y^{2}) - (\Sigma Y)^{2} })$

$r = ( ( 5 * 8509 ) - 58 * 618 ) / ( \sqrt{ ( 5 * 914 ) - ( 58 )^{2} )( 5 * 84654 ) - ( 618 )^{2} })$

$r = 0.949$

Y should increases, as X increases, because there is strong and positive correlation between variables.