A claim is published that in a certain area of high unemployment, $195 is the average amount spent on food per week by a family of four. A home economist wants to test this claim against the suspicion that the true average is lower than $195. She surveys a random sample of 36 families from the locality and finds the mean to be $193.20 with a standard deviation of $6.80. Want to prove the standard deviation is correct?
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.
A claim is published that in a certain area of high unemployment, $195 is the average amount spent on food per week by a family of four. A home economist wants to test this claim against the suspicion that the true average is lower than $195. She surveys a random sample of 36 families from the locality and finds the
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