A city has 17391 registered Democrats and 20553 registered Republicans. An organization wishes to survey equal proportions of
each group.

The council decides to survey 13 Republicans
How many Democrats should they survey? Democrats

The council should survey 11 Democrats.

Step-by-step explanation:

A proportional relationship is written as:

y = k*x

Where k is the constant of proportionality. y is the number of surveyed members, and x is the total number of registered members.

If we use the same proportion for each case, then we will use the same value of k.

We know that there are 20553 registered Republicans, and the council decides to survey 13 of them, then we will have the relation:

13 = k*20553

Now we can solve this for k:

13/20553 = k

Then the proportional relationship will be:

y = (13/20553)*x

The number of democrats they should survey can be found if we replace x by the number of registered Democrats, then we use x = 17391

this leads to:

y = (13/20553)*17391 = 11

The company should survey 11 Democrats.