13 March 2022 16:02

Which quartiles are used to calculate the interquartile range given the formula?

To find the interquartile range (IQR), ​first find the median (middle value) of the lower and upper half of the data. These values are quartile 1 (Q1) and quartile 3 (Q3). The IQR is the difference between Q3 and Q1.

How do you find the interquartile range of a quartile?

The interquartile range formula is the first quartile subtracted from the third quartile: IQR = Q3 – Q1.

Which quartile is the interquartile range?

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 is the formula for calculating quartiles?

The formula for quartiles is given by:

  1. Lower Quartile (Q1) = (N+1) * 1 / 4.
  2. Middle Quartile (Q2) = (N+1) * 2 / 4.
  3. Upper Quartile (Q3 )= (N+1) * 3 / 4.
  4. Interquartile Range = Q3 – Q1.


How do you find the range and interquartile range?

Quote from Youtube:
Range is 6 point 5 whoops let me slide this up a little bit. That's the third quartile. Minus 2 the first quartile as you can see and that's equal to 4 point 5 so our interquartile.

What is the formula for Q1 and Q3?

When the set of observations are arranged in ascending order the quartiles are represented as, First Quartile(Q1) = ((n + 1)/4)th Term. Second Quartile(Q2) = ((n + 1)/2)th Term. Third Quartile(Q3) = (3(n + 1)/4)th Term.

How do I find the third quartile?

The third Quartile of the 75th Percentile (Q3) is given as: Third Quartile(Q3)=(3(n+1)/4)th Term also known as the upper quartile. The interquartile range is calculated as: Upper Quartile – Lower Quartile.

How do you find the interquartile range example?

Q3 is the middle value in the second half of the data set. Again, since the second half of the data set has an even number of observations, the middle value is the average of the two middle values; that is, Q3 = (6 + 7)/2 or Q3 = 6.5. The interquartile range is Q3 minus Q1, so IQR = 6.5 – 3.5 = 3.

How do you find Q1 Q3 and IQR in Excel?

Quote from Youtube:
Simply click on an empty cell. And type in equals quartile open bracket and select the dataset of interest I'm going to click and drag. Then you add a comma.

How do I find the first quartile?

If the data set has an even number of elements, the median is the average of the two middlemost values. Take the median of the lower half of the data set. The median of this set is the value of the first quartile.

How do you find the 1st 2nd and 3rd quartiles?

Quote from Youtube:
When we substitute 11 for n we get 6. And if we look at the sixth data observation we find that it equals 5 therefore q2 equals 5 to find the third quartile.

How do you find Q1 and Q3 on a calculator?

There are four different formulas to find quartiles:

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

How do you find Q1 and Q3 in quartile deviation?

Calculation of quartile deviation can be done as follows,

  1. Q1 is an average of 2nd, which is11 and adds the difference between 3rd & 4th and 0.5, which is (12-11)*0.5 = 11.50.
  2. Q3 is the 7th term and product of 0.5, and the difference between the 8th and 7th term, which is (18-16)*0.5, and the result is 16 + 1 = 17.


How do you find interquartile deviation?

Quartile deviation is a statistic that measures the deviation in the middle of the data. Quartile deviation is also referred to as the semi interquartile range and is half of the difference between the third quartile and the first quartile value. The formula for quartile deviation of the data is Q.D = (Q3 – Q1)/2.

What is the formula of quartile deviation?

The Quartile Deviation can be defined mathematically as half of the difference between the upper and lower quartile. Here, quartile deviation can be represented as QD; Q3 denotes the upper quartile and Q1 indicates the lower quartile. Quartile Deviation is also known as the Semi Interquartile range.