According to the historical data, the life expectancy in Egypt is equal to the life expectancy in Morocco. A new study has been made to see whether this has changed. Records of 290 individuals from Egypt who died recently are selected at random. The 290 individuals lived an average of 63.6 years with a standard deviation of 2.8 years. Records of 240 individuals from Morocco who died recently are selected at random and independently. The 240 individuals lived an average of 63.0 years with a standard deviation of 2.6 years. Assume that the population standard deviation of the life expectancy can be estimated by the sample standard deviations, since the samples that are used to compute them are quite large. At the 0.05 level of significance, is there enough evidence to support the claim that the life expectancy, µ, in Egypt is not equal to the life expectancy, µ,, in Morocco anymore? Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.)
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.
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