If Isaac uses a coupon entitling him to a 25% discount off the purchase price before tax, how much will his bill be? Assume that
2 answers:
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The slope and intercept form is the form of the straight line equation that includes the value of the slope of the line
- Neither
- ║
- Neither
- ⊥
- ║
- Neither
- Neither
- Neither
Reason:
The slope and intercept form is the form y = m·x + c
Where;
m = The slope
Two equations are parallel if their slopes are equal
Two equations are perpendicular if the relationship between their slopes, m₁, and m₂ are;
1. The given equations are in the slope and intercept form
The slope, m₁ = 3
The slope, m₂ =
Therefore, the equations are <u>neither</u> parallel or perpendicular
- Neither
2. y = 5·x - 3
10·x - 2·y = 7
The second equation can be rewritten in the slope and intercept form as follows;
Therefore, the two equations are <u>parallel</u>
- ║
3. The given equations are;
-2·x - 4·y = -8
-2·x + 4·y = -8
The given equations in slope and intercept form are;
Slope, m₁ =
Slope, m₂ =
The slopes
Therefore, m₁ ≠ m₂
The lines are <u>Neither</u> parallel nor perpendicular
- <u>Neither</u>
4. The given equations are;
2·y - x = 2
m₁ =
y = -2·x + 4
m₂ = -2
Therefore;
Therefore, the lines are <u>perpendicular</u>
- ⊥
5. The given equations are;
4·y = 3·x + 12
-3·x + 4·y = 2
Which gives;
First equation,
Second equation,
Therefore, m₁ = m₂, the lines are <u>parallel</u>
- ║
6. The given equations are;
8·x - 4·y = 16
Which gives; y = 2·x - 4
5·y - 10 = 3, therefore, y =
Therefore, the two equations are <u>neither</u> parallel nor perpendicular
- <u>Neither</u>
7. The equations are;
2·x + 6·y = -3
Which gives
12·y = 4·x + 20
Which gives
m₁ ≠ m₂
- <u>Neither</u>
8. 2·x - 5·y = -3
Which gives;
5·x + 27 = 6
- Therefore, the slopes are not equal, or perpendicular, the correct option is <u>Neither</u>
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Answer:
a) 98.522
b) 0.881
c) The correlation coefficient and co-variance shows that there is positive association between marks and study time. The correlation coefficient suggest that there is strong positive association between marks and study time.
Step-by-step explanation:
a.
As the mentioned in the given instruction the co-variance is first computed in excel by using only add/Sum, subtract, multiply, divide functions.
Marks y Time spent x y-ybar x-xbar (y-ybar)(x-xbar)
77 40 5.1 1.3 6.63
63 42 -8.9 3.3 -29.37
79 37 7.1 -1.7 -12.07
86 47 14.1 8.3 117.03
51 25 -20.9 -13.7 286.33
78 44 6.1 5.3 32.33
83 41 11.1 2.3 25.53
90 48 18.1 9.3 168.33
65 35 -6.9 -3.7 25.53
47 28 -24.9 -10.7 266.43
Co-variance=886.7/(10-1)
Co-variance=886.7/9
Co-variance=98.5222
The co-variance computed using excel function COVARIANCE.S(B1:B11,A1:A11) where B1:B11 contains Time x column and A1:A11 contains Marks y column. The resulted co-variance is 98.52222.
b)
The correlation coefficient is computed as
(y-ybar)^2 (x-xbar)^2
26.01 1.69
79.21 10.89
50.41 2.89
198.81 68.89
436.81 187.69
37.21 28.09
123.21 5.29
327.61 86.49
47.61 13.69
620.01 114.49
sum(y-ybar)^2=1946.9
sum(x-xbar)^2=520.1
The correlation coefficient computed using excel function CORREL(A1:A11,B1:B11) where B1:B11 contains Time x column and A1:A11 contains Marks y column. The resulted correlation coefficient is 0.881.
c)
The correlation coefficient and co-variance shows that there is positive association between marks and study time. The correlation coefficient suggest that there is strong positive association between marks and study time. It means that as the study time increases the marks of student also increases and if the study time decreases the marks of student also decreases.
The excel file is attached on which all the related work is done.