Week 6
Week 6: Analysis 1 (Descriptive)
is a range of estimates consists of the minimum and the maximum calculated. The range covers the value of the parameter with the probability that it is set, refers to the probability that an interval of confidence will cover the true constant. The range of confidence interval depends on two factors: Population variation and Sample size.
Descriptive Statistics
In this topic, it will be discussed about we are interest in and experiment that we can not measure it directly. In this case how do we know the true value and the precision for the result of the quantities for the measurement actually made.
Descriptive statistics give information that describes the data in some manner. We can describe this type of statistics by using description or numbers (mean, median, mode) and using graph, figure. It is worthwhile to note that we can not use the descriptive statistics for all data. By this it means that we can use within the assumption when the data has a normal distribution that shows a characteristic of central tendency.
Mean = Sum of the values/ total number of values
Median= A set of number is found by listing the number in ascending order and then selecting the value that lies half way along the list
Exp. 1 I I I I I I I I I whereas I represents as the median of this data
Exp. 2 I I I I I I I I I I We can find the median by using I + I / 2
Mode = A set of value is that value that occur most often
Exp. 3 3 3 4 4 4 4 5 5 5 6 6 6 7 7 7 The mode is 4
The variance and standard deviation
I would like to invite you to look closely in to the 2 sets of data below.
Suppose that
the three students marks (out of 10)
In class A are 7 4 and 10
In class B are 7 7 and 7
It has been seen equal mean mark in both classes (mean = 7)
Even though class A shows the wide spread mark, in the class B are the same.
So, the variance and standard deviation are the crucial and widely used statistical quantities that contain the wide spread of information.
The Range
The range of data set is obtained by computing the difference between the largest and the smallest data value in the data set as the formula below.
Range= Largest value - Smallest value
The variance and standard deviation
I would like to invite you to look closely in to the 2 sets of data below.
Suppose that
the three students marks (out of 10)
In class A are 7 4 and 10
In class B are 7 7 and 7
It has been seen equal mean mark in both classes (mean = 7)
Even though class A shows the wide spread mark, in the class B are the same.
So, the variance and standard deviation are the crucial and widely used statistical quantities that contain the wide spread of information.
The Range
The range of data set is obtained by computing the difference between the largest and the smallest data value in the data set as the formula below.
Range= Largest value - Smallest value
Confidence interval (CI)
If the variation in population is less -> CI is narrow
If the variation in population is large -> CI is wide
If the sample size is small -> CI is wide
If the sample size is large -> CI is narrow
We will use the confidence interval for describing a measurement accuracy. It is also a measure of the stability of the estimate. This is a way to evaluate how close your measurements are to the original estimate.
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