# What is upper quartile?

## What is upper quartile?

The upper quartile, or third quartile (Q3), is the value under which 75% of data points are found when arranged in increasing order. The median is considered the second quartile (Q2). The interquartile range is the difference between upper and lower quartiles.

What are the 4 quartiles?

How Quartiles Work

• First quartile: the lowest 25% of numbers.
• Second quartile: between 0% and 50% (up to the median)
• Third quartile: 0% to 75%
• Fourth quartile: the highest 25% of numbers.

### How do you find the quartiles?

How to Calculate Quartiles

1. Order your data set from lowest to highest values.
2. Find the median. This is the second quartile Q2.
3. At Q2 split the ordered data set into two halves.
4. The lower quartile Q1 is the median of the lower half of the data.
5. The upper quartile Q3 is the median of the upper half of the data.

What is the formula of middle quartile?

The middle value between the median and the last term is the third quartile. Mathematically, they are represented as follows, When the set of observations are arranged in ascending order the quartiles are represented as, First Quartile(Q1)=((n+1)/4)th Term also known as the lower quartile.

#### How do I find the third quartile?

Quartile Formula

1. First Quartile(Q1) = ((n + 1)/4)th Term.
2. Second Quartile(Q2) = ((n + 1)/2)th Term.
3. Third Quartile(Q3) = (3(n + 1)/4)th Term.

What is the lower whisker?

Similarly, the lower whisker boundary of the box plot is the smallest data value that is within 1.5 IQR below the first quartile. Here, 1.5 IQR below the first quartile is 52.5 °F and the minimum is 57 °F. Therefore, the lower whisker is drawn at the value of the minimum, which is 57 °F.

## How many quartiles are there?

Quartiles divide the entire set into four equal parts. So, there are three quartiles, first, second and third represented by Q1, Q2 and Q3, respectively.

What is the formula for Q1 and Q3?

Formula for Lower quartile (Q1) = N + 1 multiplied by (1) divided by (4) Formula for Middle quartile (Q2) = N + 1 multiplied by (2) divided by (4) Formula for Upper quartile (Q3) = N + 1 multiplied by (3) divided by (4)

### How do you find Q1 and Q3?

Q1 is the median (the middle) of the lower half of the data, and Q3 is the median (the middle) of the upper half of the data. (3, 5, 7, 8, 9), | (11, 15, 16, 20, 21). Q1 = 7 and Q3 = 16.

How do you explain a Boxplot?

A boxplot is a standardized way of displaying the distribution of data based on a five number summary (“minimum”, first quartile (Q1), median, third quartile (Q3), and “maximum”). It can tell you about your outliers and what their values are.

#### How do I calculate the upper or lower quartile?

To find the first quartile of a set of numbers, find the median of the lowest half of the data set. This median is the first, or lowest, quartile in the data set. To find the third, or upper, quartile of a data set, instead find the median of the higher half of numbers in the set.

How to find lower quartile?

The Moore and McCabe method excludes the median from the lower half. The lower quartile is the middle number of the lower half:

• The Tukey method includes the median in the lower half.
• The Mendenhall and Sincich method uses a formula to find the position of the lower quartile.
• ## How do you calculate quartile range?

To calculate it, first order your data points from least to greatest, then determine your first and third quartile positions by using the formulas (N+1)/4 and 3*(N+1)/4 respectively, where N is the number of points in the data set. Finally, subtract the first quartile from the third quartile to determine the interquartile range for the data set.

How to find quartiles of 12 numbers?

There are four different formulas to find quartiles: Formula for Lower quartile (Q1) = N + 1 multiplied by (1) divided by (4) Formula for Middle quartile (Q2) = N + 1 multiplied by (2) divided by (4) Formula for Upper quartile (Q3) = N + 1 multiplied by (3) divided by (4)