STT 231- lecture 4
Percentile
The pth percentile is a number such that p% of the statistics falls
underneath it and (one hundred − p)% falls above it.
Median is fiftieth percentile
Image: percentile
percentile example
Suppose a pupil scored 560 on the GMAT exam and this score puts her inside the 58th
percentile.
This means 58% of check takers scored decrease than 560, and (a hundred − fifty eight)% =
forty two% scored better than 560.
First quartile
The first (or lower) quartile
Q1 (or QL) is the twenty fifth 25% percentile.
2nd quartile
Q2 is the
median or the 50th percentile.
Third (or top) quartile
Q3 (or QU ) is the seventy fifth percentile.
Quartiles
The first (or decrease) quartile, Q1, is the sort of cost that 25% of observations are smaller than
or same to it.
The second quartile, Q2 is the median, which is this type of price
that fifty% of observations are smaller than or identical to it.
The 0.33 (or top) quartile, Q3, is this kind of fee that 75% of
observations are smaller than or identical to it.
, Notice that, Q1 = twenty fifth percentile, Q2 = median = 50th
percentile, and Q3 = 75th percentile.
Image: Quartiles
Quartiles and statistics distribution
Quartiles divide the information set into four identical quarters.
Obviously, Q1 ≤ Q2 ≤ Q3.
Q1 Q2 and Q3 can be equal
calculating quartiles
First sort the facts in ascending order.
Find the median or Q2.
Now observe the bottom 1/2 of the records, i.E. All of the observations which can be under the
median function.
Median of the lowest half of of the records is the Q1
Next take on the upper half of the information, i.E. All the observations
that are above the median role.
Median of the top half of the facts is the Q3.
Instance of quartiles
Image: instance of quartiles
four
Measures of Dispersion or Variability
Range & Inter Quartile Range (IQR)
Variance & Standard Deviation
measure of dispersion
Measures of dispersion or variability quantifiy the quantity of unfold of the statistics.
We shall measure unfold of a distribution the use of:
-Range,
- Inter Quartile Range (IQR),
Percentile
The pth percentile is a number such that p% of the statistics falls
underneath it and (one hundred − p)% falls above it.
Median is fiftieth percentile
Image: percentile
percentile example
Suppose a pupil scored 560 on the GMAT exam and this score puts her inside the 58th
percentile.
This means 58% of check takers scored decrease than 560, and (a hundred − fifty eight)% =
forty two% scored better than 560.
First quartile
The first (or lower) quartile
Q1 (or QL) is the twenty fifth 25% percentile.
2nd quartile
Q2 is the
median or the 50th percentile.
Third (or top) quartile
Q3 (or QU ) is the seventy fifth percentile.
Quartiles
The first (or decrease) quartile, Q1, is the sort of cost that 25% of observations are smaller than
or same to it.
The second quartile, Q2 is the median, which is this type of price
that fifty% of observations are smaller than or identical to it.
The 0.33 (or top) quartile, Q3, is this kind of fee that 75% of
observations are smaller than or identical to it.
, Notice that, Q1 = twenty fifth percentile, Q2 = median = 50th
percentile, and Q3 = 75th percentile.
Image: Quartiles
Quartiles and statistics distribution
Quartiles divide the information set into four identical quarters.
Obviously, Q1 ≤ Q2 ≤ Q3.
Q1 Q2 and Q3 can be equal
calculating quartiles
First sort the facts in ascending order.
Find the median or Q2.
Now observe the bottom 1/2 of the records, i.E. All of the observations which can be under the
median function.
Median of the lowest half of of the records is the Q1
Next take on the upper half of the information, i.E. All the observations
that are above the median role.
Median of the top half of the facts is the Q3.
Instance of quartiles
Image: instance of quartiles
four
Measures of Dispersion or Variability
Range & Inter Quartile Range (IQR)
Variance & Standard Deviation
measure of dispersion
Measures of dispersion or variability quantifiy the quantity of unfold of the statistics.
We shall measure unfold of a distribution the use of:
-Range,
- Inter Quartile Range (IQR),
