An epidemiologic survey of roller-skating injuries in Metroville, a city with a population of 100,000 (during the midpoint of the year), produced the following data for a particular year:

Number of skaters in Metroville during any given month 12,000
Roller-skating injuries in Metroville 600
Total number of residents injured from roller-skating 1,800
Total number of deaths from roller-skating 90
Total number of deaths from all causes 900

The proportional mortality ratio (%) due to roller-skating was:

a. 90/600 × 100
b. 90/100,000 × 100
c. 90/1,800 × 100
d. 90/900 × 100

c.

Step-by-step explanation:

As per given , we have

Total number of residents injured from roller-skating =1,800

Total number of deaths from roller-skating = 90

Formula for Mortality rate :

Then, the proportional mortality ratio (%) due to roller-skating was

=

= 5%

Hence, the correct answer is c.

i think that you should ask google for the answer to that problem because if we don't know it google does

let's add {f(x)=x+1}f(x)=x+1 and {g(x)=2x}g(x)=2x together to make a new function.

f(x)+g(x) =(x+1)+(2x)=x+1+2x=3x+1

let's call this new function hh. so we have:

{h(x)}={f(x)}+{g(x)}{=3x+1}h(x)=f(x)+g(x)=3x+1

we can also evaluate combined functions for particular inputs. let's evaluate function hh above for x=2x=2. below are two ways of doing this.

method 1: substitute x=2x=2 into the combined function hh.

h(x)

h(2)

​    

=3x+1

=3(2)+1

=7

​ since h(x)=f(x)+g(x)h(x)=f(x)+g(x), we can also find h(2)h(2) by finding f(2) +g(2)f(2)+g(2).

first, let's find f(2)f(2):

f(x)

f(2)

​    

=x+1

=2+1

=3

​  

now, let's find g(2)g(2):

g(x)

g(2)

​    

=2x

=2⋅2

=4

​  

so f(2)+g(2)=3+4=\greend7f(2)+g(2)=3+4=7.

notice that substituting x =2x=2 directly into function hh and finding f(2) + g(2)f(2)+g(2) gave us the same answer!