Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

000 /af/servlet/quiz?quiz action-takeQuiz&quiz; probGuid-ONAPCOA801010000003e822

ID: 3040005 • Letter: 0

Question

000 /af/servlet/quiz?quiz action-takeQuiz&quiz; probGuid-ONAPCOA801010000003e822db00900008ct-kelly.huls Ao Aa 6. EOC Practice problem Some types of algae have the potential to cause damage to river ecosystems. The accompanying data on algae colony density (7) and rock surface area (x) for nine rivers is based on data that appeared in a scatterplot in a paper In the journal Aquatic Ecology (2010: 33-40). X 50 54 49 78 45 35 69 46 50 Y 153 48 23 36 38 182 14 185 26 Note: In the following questions, the exact values in your answers may differ from those provided due to rounding differences. Select the responses that are closest to your answers. Compute the equation of the least squares regression line. O y = 78.33 +52.89x y =-3.14x O y -3.14 +244.411x O y 244.41 3.14x What is the value of r2 for this data set? r2 =-0.57 r2 = 244.41 r2 = 0.57 O r2 = 0.32 What is the value of se for this data set? se = 63.94 O se= 0.32 O se = 0.57 O se 56.39

Explanation / Answer

Answer:

Regression line y=244.41-3.14x

r2 = 0.32

se=63.94

Relationship is negative ( coefficient is negative)

Relationship is moderate ( r=-0.564)

Regression Analysis

0.319

n

9

r

-0.564

k

1

Std. Error

63.924

Dep. Var.

y

ANOVA table

Source

SS

df

MS

F

p-value

Regression

13,374.1065

1  

13,374.1065

3.27

.1134

Residual

28,603.8935

7  

4,086.2705

Total

41,978.0000

8  

Regression output

confidence interval

variables

coefficients

std. error

   t (df=7)

p-value

95% lower

95% upper

Intercept

244.6232

94.3547

2.593

.0358

21.5098

467.7366

x

-3.1441

1.7379

-1.809

.1134

-7.2537

0.9654

Regression Analysis

0.319

n

9

r

-0.564

k

1

Std. Error

63.924

Dep. Var.

y

ANOVA table

Source

SS

df

MS

F

p-value

Regression

13,374.1065

1  

13,374.1065

3.27

.1134

Residual

28,603.8935

7  

4,086.2705

Total

41,978.0000

8  

Regression output

confidence interval

variables

coefficients

std. error

   t (df=7)

p-value

95% lower

95% upper

Intercept

244.6232

94.3547

2.593

.0358

21.5098

467.7366

x

-3.1441

1.7379

-1.809

.1134

-7.2537

0.9654