Answer:
If I budget 12% of my monthly income for grocerises and I earn $950 bi-weekly.
Now, the term 'Biweekly' has an ambiguity. Given that in some countries like the UK, Ireland and Australia it means 'Every two weeks' but in other countries it means 'Twice every week'. In this case, we're going to solve both cases:
In this case, I would earn $1900 a month. Now, 12% percent of my monthly income is: 0.12 × $1900 = $200.
Therefore, I would spend $200 a month in groceries.
In this case, I would earn $1900 a week or $7600 a month . Now, 12% percent of my monthly income is: 0.12 × $7600 = $912.
Therefore, I would spend $912 a month in groceries.
Probably, the exercise refers to case #1. But just in case, I considered both cases.