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
![Covariance=\frac{sum[(y-ybar)(x-xbar)]}{n-1}](https://tex.z-dn.net/?f=Covariance%3D%5Cfrac%7Bsum%5B%28y-ybar%29%28x-xbar%29%5D%7D%7Bn-1%7D)
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
![Correlation coefficient=r=\frac{sum[(y-ybar)(x-xbar)]}{\sqrt{sum[(x-xbar)]^2sum[(y-ybar)]^2} }](https://tex.z-dn.net/?f=Correlation%20coefficient%3Dr%3D%5Cfrac%7Bsum%5B%28y-ybar%29%28x-xbar%29%5D%7D%7B%5Csqrt%7Bsum%5B%28x-xbar%29%5D%5E2sum%5B%28y-ybar%29%5D%5E2%7D%20%7D)
(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.
The types of correlation seen between positive correlation, negative correlation, or no correlation, in the variables is:
- a. Height of a person and how often he or she attends religious services. - No correlation
- (b.)Average property tax in a school district and salary of teachers - Positive correlation
- (c.)Weight of a person and shoe size. - Positive correlation
<h3>What is the correlation between property taxes and teacher salaries?</h3>
One of the main sources of funding for school districts is the property tax charged. This means that increased property taxes will lead to more money being available for teacher salaries which might then increase. There is therefore a positive correlation between the two.
The same is true for the weight of a person and shoe size. This is because the heavier a person is, the larger their shoe size according to research.
There is however no correlation between the height of a person and their attendance of religious services.
Find out more on positive correlation at brainly.com/question/17180881
#SPJ1
Answer:
should be 3^X = 7 and X = log7/log3
Step-by-step explanation:
Replace m with 46x10^4 in the equation and solve.
0.036(46x10^4)^3/4 = 635.87
Round to 636
The answer is A.
Answer:
m∠CEB is 55°
Step-by-step explanation:
Since ∠ADE = 55°, and ∠ADE is half of ∠ADC because ED bisects ∠ADC. Bisect means to cut in half.
∠ADC = 110° because it is double of ∠ADE.
Since AB║CD and AD║BC, the two sets of parallel lines means this shape is a parallelogram. In parallelograms, <u>opposite angles have equal measures</u>.
∠ADC = ∠CBE = 110°
All quadrilaterals have a sum of angles 360°. Since ∠DCB = ∠BAD and we know two of these other angles are each 110°:
360° - 2(110°) = 2(∠DCB)
∠DCB = 140°/2
∠DCB = ∠BAD = 70°
∠DCB was bisected by EC, which makes each divided part half.
∠DCE = ∠BCE = (1/2)(∠DCB)
∠DCE = ∠BCE = (1/2)(70°)
∠DCE = ∠BCE = 35°
All triangles' angles sum to 180°.
In ΔBCE, ∠BCE = 35° and ∠CBE = 110°.
∠CEB = 180° - (∠BCE + ∠CBE)
∠CEB = 180° - (35° + 110°)
∠CEB = 55°
Therefore m∠CEB is 55°.
