Solution :
The term 'literacy rate' provides the ability of a person who is from a definite age group can read or write.
a). 
does not determine the rate at which the variable explains another, but it explains the amount the amount of variability in one of the variables as explained by the other variable.
b). The slope given provides an expected improvement but it cannot guarantee the improvement. The value may be less or it could be more also.
The regression model provides the prediction and not the actual values.
Total amount = $80
Amount left= $54.74
So amount spent = 80 - 54.74 = $25.26
Let the number of pounds be ‘x’
8.42 x = 25.26
x = 3
Ans: She bought 3 pounds of coffee
X=amount of money at first.
we can suggest this equation:
4/7 x=28
x=(28*7)/4
x=196/4
x=49
Answer: he have originally $49.
