To find the mean, you add all the elements together, then divide by the number of elements. 
Like this:
(45+48+49+40+53)/5=47
in other words the correct answer is 47 inches. 
EDIT: Did the foolish mistake, of using the wrong numbers the first time. Fixed now and the answer is correct.
        
                    
             
        
        
        
Distance=amount of gas times miles per gallon
distance=y
amount of gas=x
mpg=?
given
y=300
x=10
300=10 times ?
divide both sidesj by 10
30=?
equation is 
y=x times 30 or
y=30x
        
             
        
        
        
Answer:
6 times 10^3
Step-by-step explanation:
You multiply 3 and 2 together and 10^7 and 10^-4 together. 3x2 is equal to 6 and 10^7 times 10^-4 is the same as 10^7-4 which is equal to 10^3. Therefore, the answer is 6 times 10^3.
If this has helped please mark as brainliest
 
        
             
        
        
        
Answer:
the dark purple in the bottom, brown reddish one light purple one in the bottom 
Step-by-step explanation:
 
        
             
        
        
        
Y = 2x +13
We know the slope to be 2 because lines that are parallel have the same slope. Then we can solve using slope-intercept form and  the known point. 
y = mx + b ----> Input known values
7 = (2)(-3) + b ---> Multiple
7 = -6 + b ----> Subtract 3 from both sides
13 = b
Now we can use the y-intercept found and the slope to write the equation above.