Hello tutors, I tried working on this by watching stats videos on youtube and pieces of information from this site. Can you verify if the workup is correct? Your help is appreciated. This class is not my strenght so it will be a great achievement. Thank you!

Indicate whether the following generalizations suggest a positive or negativerelationship. Also speculate aboutwhether or notthese generalizations reflectsimple cause-effect relationships.

(a) Preschool children who delay gratification (postponing eating one marshmallow towin two) subsequently receive higher teacher evaluations of adolescent competencies.

This is a negative relationship. This is not a cause effect relationship as there many factors that play a role inchildren receiving higher evaluations. For instance, the child may not delay postponing marshmallow simply because it doesn't like it. Additionally, student ranking.

(b) College students who take longer to finish a test perform more poorly on that test

This is a negative relationship. This is not a cause effect relationship as students who take longer may fall under different factors such as carefulness, anxiety- ability for test taking, underlining causes as reading abilities that may slow down understanding, orsimply reviewing material, to name a few.

(c) Heavy smokers have shorter life expectancies.

This is a negative relationship. This is not a cause effect relationship as heavy smokers may potentially live a healthier lifestyle such as eating, exercise, andgenetics.

(d) Infants who experience longer durations of breastfeeding score higher on IQ tests in later childhood.

This is a negative relationship. This is not a cause effect relationship as infantsas several factors can impact thechildsIQ score such as education, learning ability, resources, and even privileges, to name a few.

Exercise 7.8

Each of the following pairs represents the number of licensed drivers (X )and thenumber of cars (Y )for seven houses in my neighborhood:

Drivers (X)

5

5

2

2

3

1

2

Cars (Y)

4

3

2

2

2

1

2

(a) Construct a scatterplot to verify a lack of pronounced curvilinearity.

(b) Determine the least squares equation for these data. (Remember, you will first haveto calculate r, SSy and SSx)

(c) Determine the standard error of estimate, sy|x, given that n = 7.

(d) Predict the number of cars for each of two new families with two and five drivers

Divide 20/7 variable rows. Divide 16/7 variable rows Drivers (X) Cars (Y) XY X2 Y2 20 25 16 15 25 9 4 4 4 NHWNNUU NANNNWA 4 4 4 6 20 16 54 72 42 MEAN 2.851742857 2.285714286 EX=2 Ex 2=7 0 EY=16 EXY=54 2 Sxx = 72 - 1/7 (20)2 = SXX =14.8571429Syy = 42 - 1/7 (16) 2= Syy = 5.4285174 Sxy = 54 - 1/7 (20) (16) Sxy = 8.2857143 0.92261 R= 8.2857143 = 291 0.9226129 RE 1Y= a+bx 7 (54) - (20) a = n Exy- Ex Zy S (16) nc2 - (Ex)2 7 (72) - (20)2 b = Zy-m Ex 16 - (0.557692308)_(20) n 7 y= 0.692 + 0.558xDouble check with excel Drivers (X) Cars (Y) NHWNNUU NHNNN WA Slope 0.557692308 Y Intercept 0.692307692 Values are SXX=14.8571429 Syy=5.4285714 Sxy =8.2857143 r=0.923 y=0.692+0.558x