Answer:

With
representing the slope we have that:


And we are interest on this case the interpretation about the slope and we can conclude that:
For every unit increase in literacy rate (percent of the population that is literate) the age difference (husband minus wife age) falls by 0.0437 units, on average.
Step-by-step explanation:
For this case we have that the regression model adjusted between age difference (husband minus wife age) representing the y variable and literacy rate (percent of the population that is literate) representing the variable x is given by:
where 
And we know that the method used in order to adjust the regression line was least squares.
For this case our dependent variable is y = age difference (husband minus wife age) and the independent variable is x=literacy rate (percent of the population that is literate)
If we compare the regression model adjusted with the linear regression model:

With
representing the slope we have that:


And we are interest on this case the interpretation about the slope and we can conclude that:
For every unit increase in literacy rate (percent of the population that is literate) the age difference (husband minus wife age) falls by 0.0437 units, on average.
Answer:
Step-by-step explanation:
Plan 2: x= number of months
y= the cost per call
19x + 0.04y
19(4) + 0.04(20)
76 + 0.8
76.8
So the total will be $76.8
For the first picture..........
|AB| |BD|
-----=-----
|AC| |DC|
x+8 10
-----=----
2x-5 14
10(2x-5)=14(x+8)
20x-50 = 14x+112
20x-14x = 112+50
6x = 162
x= 162/6
x=27.....
For the second picture.......
AD| |AC|
-----=-----
|DB| |CB|
3 4
--=---
x 7.5
4×X = 3×7.5
x = 22.5/4
x = 5.625....