Consider two graphs for the amount of the first bill for 80 new residential phone customers. At least one graph will contain sufficient information to answer any question. Exactly, find the 8th percentile of the 80 bill amounts. Note: the lowest 21 amounts are visible, the middle 56 are obscured by the coffee spill, and the highest 3 amounts are also visible. What is the relative frequency of bill amounts that are at least 90?
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.
Consider two graphs for the amount of the first bill for 80 new residential phone customers. At least one graph will contain sufficient information to answer any question.
Exactly, find the 8th percentile of the 80 bill amounts.
Note: the lowest 21 amounts are visible, the middle 56 are obscured by the coffee spill, and the highest 3 amounts are also visible.
What is the relative frequency of bill amounts that are at least 90?
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