Question

The probability distribution histogram shows the mass distribution of sedimentary rocks in the collection at a museum of natural history.
What is P(10≤X<35) ?

Enter the probability of the event in the box.

Please, please help!

Answer 1

The p statement asks for the probability that 10kg is less than or equal to the mass and that the mass is less than 35kg. To work this out, add the probabilities of all the bars on the histogram where the mass fits this range: the 10-15kg, 15-20kg, 20-25kg, 25-30kg and 30-35kg bars. When probability events are mutually exclusive (i.e. the mass can only be represented by one of the bars, not multiple bars), simply add the probabilities together. 0.25 + 0.2 + 0.2 + 0.1 + 0.1 = 0.85. The probability is 0.85 that the mass will be greater than or equal to 10kg and less than 35kg.