Study the given table and answer the question that follows.

The table shows the number of eggs produced in five farms.

Year	Farm
	P	Q	R	S	T
2010	1020	1418	1630	1740	1580
2011	1260	1390	1460	1530	1620
2012	1120	1765	1480	1515	1640
2013	1465	1555	1746	1418	1545

What is the respective ratio of the dozens of eggs produced by farm P to farm T in the year 2011?

The correct option is 7∶9.

To find the respective ratio of the dozens of eggs produced by farm P to farm T in the year 2011, we can analyze the data given in the table:
1. Locate the row for the year 2011.
2. In the year 2011, the number of eggs produced by farm P is 1260.
3. In the year 2011, the number of eggs produced by farm T is 1620.

Since 1 dozen consists of 12 eggs, the number of dozens of eggs produced by each farm is:
- For farm P:
$\frac{1260}{12}=105$ dozens.
- For farm T:
$\frac{1620}{12}=135$ dozens.

Now, we find the respective ratio of the dozens produced by farm P to farm T:
$\text{Ratio}=\frac{105}{135}$

We can simplify this fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 15:
$\frac{105÷15}{135÷15}=\frac{7}{9}$

(Note that the ratio of the number of individual eggs, 1260∶1620, also simplifies to the same ratio 7∶9 because the conversion factor of 12 for dozens cancels out:
$\frac{1260}{1620}=\frac{126}{162}=\frac{126÷18}{162÷18}=\frac{7}{9}$ .)

Thus, the respective ratio of the dozens of eggs produced by farm P to farm T in 2011 is 7∶9.