Answer:
The mean until the supplement is published is 140 months, while the standard deviation is of 11.8 months.
Step-by-step explanation:
The Poisson distribution is used to solve this question, as we have only the mean. In this distribution, the standard deviation is the square root of the mean.
In this question, we have that:
Species are discovered at a rate of once every 7 months.
A supplement to a guide is planned to be published after 20 new species have been discovered.
a) What are the expected value and standard deviation of the number of months (treated as a continuous measure of time) until the supplement is published?
Mean is: 7*20 = 140 months.
Standard deviation is [tex]\sqrt{140}[/tex] = 11.8 months.
The mean until the supplement is published is 140 months, while the standard deviation is of 11.8 months.
