Final answer:
The IQR for the data set represented by the stem plot is the difference between Q3 and Q1, which is 7, corresponding to the fourth option.
Step-by-step explanation:
The Interquartile Range (IQR) for the data represented by the stem plot is the range of the middle 50 percent of the data values, calculated by subtracting the first quartile (Q1) from the third quartile (Q3). In this case, the IQR is calculated as 9 minus 2 which gives us an IQR of 7. Since this is one of the given options, we can confidently say that the answer is Option 4: 7.