For the past several years, the Philadelphia Fire Departments has been keeping track of the number of fire hydrants that been opened illegally daily during heat waves. These data(rounded to the nearest 10) are given in the table below. Use the information to calculate how many hydrants the department should expect to be opened per day during the upcoming heat wave also find the Standard deviation of number of fire hydrants opened. Hydrants opened 20 30 40 50 60 70 Days 14 12 15 11 9 1
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
For the past several years, the Philadelphia Fire Departments has been keeping track of the number of fire hydrants that been opened illegally daily during heat waves. These data(rounded to the nearest 10) are given in the table below. Use the information to calculate how many hydrants the department should expect to be opened per day during the upcoming heat wave also find the Standard deviation of number of fire hydrants opened.
Hydrants opened 20 30 40 50 60 70
Days 14 12 15 11 9 1
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