z-scores (pt. 2)
pnorm_vis
Use the haffutils::pnorm_vis function in conjunction with pnorm for the following
problems:
## load package here
## what percentage of the data lies left of a z-score of 1.35?
## what percentage of the data lies between a z-score of -1.9 and 2.1?
z-score/probability practice
## what percentage of the data lies right of a z-score of 0.53?
## what percentage of the data lies left of a z-score of -1.88?
## what percentage of the data lies left of a z-score of 2.25?
## what percentage of the data lies between a z-score of -1.88 and 2.25?
## what percentage of the data lies between a z-score of 1.7 and 2.7?
## 75% of the data in a normal distribution lies to the right of what z-score?
## 52% of the data in a normal distribution lies right of what z-score?
## 17% of the data in a normal distribution lies left of what z-score?
## 30% of the data in a normal distribtuion lies between which two z-scores? Assume an equal number above/below the mean.
z-score/probability word problems
## the occurence of tornadoes by year in a certain state is normally distribted
## with a mean of 14 and a standard deviation of 3.1. What is the probability of
## seeing more than 16 tornadoes in a given year?
## the occurence of flash floods by year in a certain state is normally
## distribted with a mean of 31 and a standard deviation of 5.5. What is the
## probability of seeing fewer than 20 flash floods in a given year?
## the occurence of forest fires by year in a certain country is normally
## distribted with a mean of 103 and a standard deviation of 17. What is the
## probability of seeing between 68 and 137 forest fires in a given year?