I would say that the correct answer that best defines the two quantities that are measured to find the call rate of a phone company is A. the quantity of price measured in dollars depends on the quantity of time measured in minutes.
Answer:
It will take the apprentice 24 days working alone
Step-by-step explanation:
Let the number of days it takes the apprentice be x
It will take the landscaper x/3 ( since he is three times faster)
The rate for both will be 60/6 = 10 sq m per day
Rate for apprentice is 60/x
rate for the boss is 60/x/3 = 180/x
Adding the rates together;
60/x + 180/x = 10
240/x = 10
240 = 10x
x = 240/10
x = 24 days
Answer:
True,
Definition of equation for you: a statement that the values of two mathematical expressions are equal (indicated by the sign =).
I see this as the difference in their current years is 12, and the difference between the number of years they both age in human years is 3, so after 4 human years they become the same age.
Answer:
a) r=-0.719
b) y=10.642-0.976x
c)Predicted y=7.714
Step-by-step explanation:
a)
sumx=1+4+6+7=18
sumy=9+7+8+1=25
sumxy=1*9+4*7+6*8+7*1=92
sumx²=1²+4²+6²+7²=102
sumy²=9²+7²+8²+1²=195
n=number of observation=4
The correlation coefficient is computed by following formula
![r=\frac{nsumxy-(sumx)(sumy)}{\sqrt{[nsumx^{2} -(sumx)^2][nsumy^2-(sumy)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bnsumxy-%28sumx%29%28sumy%29%7D%7B%5Csqrt%7B%5Bnsumx%5E%7B2%7D%20-%28sumx%29%5E2%5D%5Bnsumy%5E2-%28sumy%29%5E2%5D%7D%7D)
![r=\frac{4(92)-(18)(25)}{\sqrt{[4(102) -(18)^2][4(195)-(25)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B4%2892%29-%2818%29%2825%29%7D%7B%5Csqrt%7B%5B4%28102%29%20-%2818%29%5E2%5D%5B4%28195%29-%2825%29%5E2%5D%7D%7D)
![r=\frac{368-450}{\sqrt{[408 -324][780-625]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B368-450%7D%7B%5Csqrt%7B%5B408%20-324%5D%5B780-625%5D%7D%7D)
![r=\frac{-82}{\sqrt{[84][155]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B-82%7D%7B%5Csqrt%7B%5B84%5D%5B155%5D%7D%7D)

By rounding r to 3 decimal places we get r=-0.719.
b)
The regression equation can be written as y=a+bx
We have to find "a" and "b" for regression equation




b=-0.976
xbar=sumx/n
xbar=18/4=4.5
ybar=sumy/n
ybar=25/4=6.25
a=ybar-b(xbar)
a=6.25-(-0.976)4.5
a=6.25+4.392
a=10.642
Thus, the regression equation is
y=a+bx
y=10.642-0.976x
c)
The predicted value of y for x=3 can be computed by putting the value of x in regression equation
y=10.642-0.976(3)
y=10.642-2.928
y=7.714
Hence, the predicted y-value for x=3 is 7.714.