Research at the SA weather centre in the Northern Cape recorded the number days the weather reached 38°C, first recorded in 1875. The numbers form a normal distribution with a mean of µ = 9.6 and a standard deviation of σ = 1.9. To see if the data showed any evidence of global warming, they also computed the average number of days (M = 12.25) the temperature reached 38°C, over the last 4 years. Do the data indicate that the past 4 years have had significantly more 38°C days that would be expected for any random sample from this population? Use a one tailed test with α = 0.05.
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.
Research at the SA weather centre in the Northern Cape recorded the number days the weather reached 38°C, first recorded in 1875. The numbers form a
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