# How do you calculate q1 and q3?

Steps:
1. Step 1: Put the numbers in order.
2. Step 2: Find the median.
3. Step 3: Place parentheses around the numbers above and below the median. Not necessary statistically, but it makes Q1 and Q3 easier to spot.
4. Step 4: Find Q1 and Q3.
5. Step 5: Subtract Q1 from Q3 to find the interquartile range.
A.

### How do you find the first and third quartile?

To find the quartiles of this data set, use the following steps:
1. Order the data from least to greatest.
2. Find the median of the data set and divide the data set into two halves.
3. Find the median of the two halves.
• #### What are the quartiles in a box and whisker plot?

A five statistical summary can be represented graphically as a box and whisker plot (or box plot). The first and third quartiles are the ends of the box, the median is indicated with a vertical line in the interior of the box, and the minimum and maximum are the ends of the whiskers (unless an outlier is present).
• #### How do you find the first and third quartile?

To find the quartiles of this data set, use the following steps:
1. Order the data from least to greatest.
2. Find the median of the data set and divide the data set into two halves.
3. Find the median of the two halves.
• #### What is an interquartile range in math?

The interquartile range (IQR) is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.
B.

### What does the third quartile tell you?

Mathwords: Third Quartile. For a set of data, a number for which 75% of the data is less than that number. The third quartile is the same as the median of the part of the data which is greater than the median. Same as 75th percentile.
• #### What is the first quartile?

Lower Quartile. Q1. For a set of data, a number for which 25% of the data is less than that number. The first quartile is the same as the median of the data which are less than the overall median. Same as the 25th percentile.
• #### What is a box and whisker plot?

A box and whisker plot (sometimes called a boxplot) is a graph that presents information from a five-number summary. In a box and whisker plot: the ends of the box are the upper and lower quartiles, so the box spans the interquartile range. the median is marked by a vertical line inside the box.
• #### Do quartiles include the median?

Use the median to divide the ordered data set into two halves. Do not include the median into the halves. The lower quartile value is the median of the lower half of the data. The upper quartile value is the median of the upper half of the data.
C.

### What is the definition of third quartile?

Q3. For a set of data, a number for which 75% of the data is less than that number. The third quartile is the same as the median of the part of the data which is greater than the median. Same as 75th percentile. See also.
• #### How do you find the first and third quartile?

The first quartile, denoted by Q1 , is the median of the lower half of the data set. This means that about 25% of the numbers in the data set lie below Q1 and about 75% lie above Q1 . The third quartile, denoted by Q3 , is the median of the upper half of the data set.
• #### How do you find the lower and upper quartile?

We also know that for a set of n ordered numbers the median is the (n + 1) ÷ 2 th value. Similarly, the lower quartile divides the bottom half of the data into two halves, and the upper quartile also divides the upper half of the data into two halves. Lower quartile is the (n + 1) ÷ 4 th value.
• #### How do you find the median of a number?

To find the median number:
1. Put all the numbers in numerical order.
2. If there is an odd number of results, the median is the middle number.
3. If there is an even number of results, the median will be the mean of the two central numbers.

Updated: 22nd September 2018