Quiz: Histogram, boxplot, and conditional probability

1   Histogram and boxplot

You collected these 16 water quality samples in mg/L.

1. Draw a histogram manually. Split $[0, 360]$ into six bars.
2. Draw the boxplot manually.

Show your full work!

2   Conditional probability

A chemical company has a bad history of failing to comply with an environmental law. A total of 600 out of 10,000 samples from their fertilizer product contained too much nitrogen. Out of the same 10,000 samples, a total of 7,500 contained too much phosphorus. Out of those 7,500 samples that failed the phosphorus test, 400 contained too much nitrogen.

1. What is the probability of failing both the nitrogen and phosphorus tests?
2. Bonus (20 points): What is the probability of failing either the nitrogen or phosphorus tests?