The results of a lab experiment showed positive results for 15

Question

test subjects, which is 20%
of t,
the total number of subjects tested.

Which statement explains how to calculate t,
the total number of test subjects?

Select the answer that is completely correct.

Responses

Since 15
is 20%
of the whole, set up the proportion 1520=t100.
Next, solve for t.
The solution is 75
total test subjects.
Since 15 is 20 percent of the whole, set up the proportion Next, solve for The solution is 75 total test subjects.

Since 15
is 20%
of t,
set up the proportion 15t=20100.
If 15t=20100,
then t15=10020.
Next, solve for t.
The solution is 75
total test subjects.
Since 15 is 20 percent of t textsf comma set up the proportion If 15 over t is equal to 20 over 100 textsf comma then Next, solve for The solution is 75 total test subjects.

Since 15
is 20%
of the whole, set up the proportion 15t=20100.
If 15t=20100,
then t15=10020.
Next, solve for t.
The solution is 30
total test subjects.
Since 15 is 20 percent of the whole, set up the proportion If 15 over t is equal to 20 over 100 textsf comma then Next, solve for The solution is 30 total test subjects.

Since 20%
of the 15
tested positive, set up the proportion t15=20100.
If t15=20100,
then 15t=10020.
Next, solve for t.
The solution is 30
total test subjects.
Since 20 percent of the 15 tested positive, set up the proportion If t over 15 is equal to 20 over 100 textsf comma then Next, solve for The solution is 30 total test subjects.

Answer 1

To find the total number of test subjects \( t \) when 15 subjects tested positive and this represents 20% of the total, we can set up a proportion. The correct setup is:

\[ \frac{15}{t} = \frac{20}{100} \]

This states that 15 is to the total number of subjects \( t \) as 20 is to 100 (the total percentage).

To solve for \( t \):

1. Cross-multiply: \( 15 \times 100 = 20 \times t \)
2. This gives us: \( 1500 = 20t \)
3. Now, divide both sides by 20 to isolate \( t \): \[ t = \frac{1500}{20} = 75 \]

Thus, the solution is 75 total test subjects.

The best statement from your options is:

"Since 15 is 20 percent of the whole, set up the proportion If 15 over t is equal to 20 over 100, then Next, solve for The solution is 75 total test subjects."

This statement correctly describes the method and arrives at the correct total number of test subjects.