# If you could help me understand this problem, I’d greatly appreciate it. The natural remedy echinace

If you could help me understand this problem, I’d greatly appreciate it.

The natural remedy echinacea is reputed to boost the immune system, which will reduce flu and colds. A 6-month study was undertaken to determine whether the remedy works. From this study, the following probability distribution of the number of respiratory infections per year (X) for echinacea users was produced:

X01234

P(X)0.3370.3220.2060.0760.059

Find the following probabilities:

A. An echinacea user has more than one infection per year

B. An echinacea user has no infections per year

C. An echinacea user has between one and three (inclusive) infections per year

I know how to get the variance, mean, and standard deviation. I get stuck, however, when I have to figure out only part of it (like figuring out the probability of having more than one infection per year). Thank you in advance for your help.