Final answer:
To calculate the proportion of students who picked 7, divide the number of students who picked 7 by the total number of students and round the answer to three decimal places.
Step-by-step explanation:
To calculate the proportion of students who picked 7:
Step 1: Divide the number of students who picked 7 (51) by the total number of students (180).
Step 2: Divide the result by 10 (the number of options available) to get the proportion.
Step 3: Round the answer to three decimal places.
Therefore, the proportion of students who picked 7 is 0.283.