The yearly incomes received by 30 randomly selected Quantitative Students in some selected areas in Ghana (to the nearest GHC 000) are as follows: 20 25 26 30 32 40 22 25 26 30 32 48 22 25 26 30 36 52 23 26 28 30 36 60 25 26 28 32 38 61 (a) Find the three measures of central tendencies. [You are not required to form a frequency distribution] (b) Calculate the measures of dispersion. (c) Calculate the coefficient of skewness and comment on the result.
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.
QUESTION
The yearly incomes received by 30 randomly selected Quantitative Students in some selected areas in Ghana (to the nearest GHC 000) are as follows:
20 25 26 30 32 40
22 25 26 30 32 48
22 25 26 30 36 52
23 26 28 30 36 60
25 26 28 32 38 61
(a) Find the three measures of
[You are not required to form a frequency distribution]
(b) Calculate the measures of dispersion.
(c) Calculate the coefficient of skewness and comment on the result.
(d) Calculate 90 and 95 per cent confidence intervals for the population mean.
Step by step
Solved in 4 steps
