Q&A for How to Find the IQR

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How do I find the IQR when the upper and lower quartile are the same number?

Community Answer

Find the IQR by subtracting Q1 from Q3. If they are the same number, the IQR equals zero.

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Question

Can the IQR be negative?

Community Answer

No, if it is done correctly, all numbers should be in ascending order, therefore the first quartile would be smaller or the same as the third quartile.

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Question

How do I find IQR of 1,3,4,5,8,9,10,11,12,14,16?

Community Answer

In 1,3,4,5,8,9,10,11,12,14,16 the median for the lower quartile is 4 and the median for the upper quartile is 12. Subtract Q3 by Q1 and that would make it 12-4 and 12-4= 8.

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Question

If I have two middle numbers, can I add them together then subtract?

Community Answer

No, if the median (middle numbers) are 2 and 3 for example, then the median would be 2.5.

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Question

Is the inter quartile range the same as the median?

Community Answer

No. You have to find the median first, then find the median again of the two sides of the original median, and subtract.

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What should I do if there are four numbers in one area?

Community Answer

Find the median of the four numbers. For example, with 4, 6, 8, 10 then it's 7.

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Question

Can the IQR be a negative numbler?

Community Answer

No. If you do it right, you should have a number equal to or greater than zero.

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When using the formula, do I add the two numbers in the quartile together and then subtract them?

Community Answer

The quartiles of any distribution are the values with cumulative proportions 0.25 and 0.75. The interquartile range IQR is the distance between the first and third quartiles of a distribution. (a) What is the value of the IQR for the standard Normal distribution? (Round your answer to four decimal places.) (b) There is a constant c such that IQR = cσ for any Normal distribution N(μ, σ). What is the value of c? (Round your answer to four decimal places.)

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Question

Do I add the two numbers in quartile 3 and 1 together?

Community Answer

No, you don't add them. You must subtract the two quartiles; the answer will be the IQR.

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What do I do when Quartile 3 is larger than Quartile 1?

Community Answer

It shouldn't be larger than quartile 1. Make sure you have arranged your data set in ascending order before finding your quartiles.

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Question

How do I determine the carnality of the subset of any given set?

Community Answer

Use the formula 2 to the power n, when = the number of terms. For example: 2,3,4,7,9. The are 5 numbers. 2 to the power 5 = 32. 32 is the max number subset which could be made out of 5 terms.

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Question

How do I use the IQR to find outliers?

Community Answer

The IQR is not made to find outliers. To find outliers, just look at the data set.

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Question

How do I separate sets of data in quarters when finding the IQR?

Community Answer

First, you order the data in ascending order, then you split it. If it is even, the line will be in between the two middle numbers, but if it is odd the middle number will be the line. Now you have the first quartile and third quartile.

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Question

What is the reason for finding the IQR?

Community Answer

The IQR tells us how the range of variability should look within a data set. This means that if the average score on a test is 80%, and the IQR is 14%, you should expect the highest score in the class to be 94% and the lowest score to be 66%. IQRs are often used in science to make sure that all experiment results are accurate, as mistakes can happen that will produce wonky results. By using IQR, scientists can determine which data sets look like they were produced by mistake.

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Question

How do I calculate Q1 and Q3 of a data set?

Ngong remillard

Community Answer

To calculate the Q1 and Q3 of the data set. First, arrange the data set in ascending order. Then continue by finding the midpoint from the Q1 and Q3. Example. 3, 6, 2, 8, 7, 9. Arrange the data. 2, 3, 6, 7, 8, 9. Q1 is 3 and Q3 is 8.

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Question

What do I do if the median is the exact same number in the first half?

Community Answer

To find the median of any set of numbers, put them in order from smallest to greatest.

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Question

How can I determine an outlier in a data set using the IQR?

Community Answer

To calculate outliers of a data set, you'll first need to find the median. Then, get the lower quartile, or Q1, by finding the median of the lower half of your data. Do the same for the higher half of your data and call it Q3. Find the IQR by finding the difference between the two quartiles.

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Question

If I have 8 range numbers, what do I do?

Community Answer

If you have 8 range numbers then it may be better to determine the Interquartile range of each set of four numbers.

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Question

What do I do if I end up with 5 numbers?

Community Answer

If you have five numbers then you have an odd data set. You can determine the range out of this data set.

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Question

Given the scores -5, -3, -2, 0, 1, 4, 4, 5, 7, 10, how can I find the inter quartile range of them?

Community Answer

The median of the set is between 1 and the first 4. This gives us 2 sets. Q1 is the median of the first set. Q3 is the median of the second set. Q1 = -2 Q3 = 7 IQR = 7 - (-2) = 9

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Question

What is the interquartile range of these numbers 4 5 6 7 8 9 10?

Randy Randomson

Community Answer

The median is 7, the Q3 is 9, and the Q1 is 5. From there you subtract the Q1, 5, from the Q3, 9. After that, you get your answer with an IQR of 4.

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