Question

A second question arises from the data: “Is secchi depth related to P concentrations in the study lakes?” Using excel, choose the appropriate test to address this research question and interpret the results. Produce an appropriate figure for these data showing all relevant information

Catchement Type	Lake	P (ug/L)	Secchi Depth (m)
Forested	Vaudray	1.0	7.9
		1.1	7.4
		1.2	8.9
	Hannah	1.3	7.3
		1.3	7.2
		1.4	7.6
	Rice	3.7	7.0
		3.0	7.3
		3.5	7.2
Agriculture	Chemong	23.0	2.3
		22.0	2.2
		23.5	2.3
	Buckhorn	19.7	3.1
		20.1	3.5
		18.5	3.5
	Long	26.3	2.2
		28.1	2.3
		27.0	2.2
	Kushog	26.1	2.0
		25.9	1.9
		27.2	1.7
Residential	Osisko	15.8	3.5
		13.5	3.3
		15.1	3.7
	Whitney	13.5	3.6
		14.1	4.2
		14.5	3.0
	Eel	9.3	3.5
		10.7	4.0
		8.9	4.3

Answer 1

The scatterplot is:

There is a negative relationship between the variables.

The hypothesis being tested is:

H0: β1 = 0

H1: β1 ≠ 0

The p-value from the output is 0.0000.

Since the p-value (0.0000) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that the slope is significant.

	r²	0.884
	r	-0.940
	Std. Error	0.782
	n	30
	k	1
	Dep. Var.	P
ANOVA table
Source	SS	df	MS	F	p-value
Regression	130.2468	1	130.2468	212.99	1.29E-14
Residual	17.1229	28	0.6115
Total	147.3697	29
Regression output				confidence interval
variables	coefficients	std. error	t (df=28)	p-value	95% lower	95% upper
Intercept	7.4202
Depth	-0.2201	0.0151	-14.594	1.29E-14	-0.2510	-0.1892