Basic Arithmetic : Basic Statistics

Study concepts, example questions & explanations for Basic Arithmetic

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Example Questions

Example Question #253 : Statistics And Probability

\(\displaystyle \small 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 , 100\)

Using the data above, find the median. 

Possible Answers:

\(\displaystyle \small 6\)

\(\displaystyle \small 10\)

\(\displaystyle \small 7\)

\(\displaystyle \small 5\)

\(\displaystyle \small 4\)

Correct answer:

\(\displaystyle \small 6\)

Explanation:

The median is defined as the center data value of the data set. This data set is already set in numerical order: 

\(\displaystyle \small 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 , 100\).

Since there is an odd number of data values, \(\displaystyle \small 11\), we subtract one, \(\displaystyle \small 11-1=10\), and then divide ten in half, \(\displaystyle \small 5\). This means that there must be five data values on either side of the median. To satisfy this requirement, the median must be at the sixth spot.

Thus for this data set: 

\(\displaystyle \small 1, 2, 3, 4, 5, \textbf{6}, 7, 8, 9, 10 , 100\), the median is \(\displaystyle \small 6\)

Example Question #1674 : Algebra 1

\(\displaystyle \small \small 2, 2, 3, 4, 5, 6\)

Using the data above, find the median. 

Possible Answers:

\(\displaystyle \small 3. 5\)

\(\displaystyle \small 4\)

\(\displaystyle 7\)

\(\displaystyle \small 3\) and \(\displaystyle \small 4\)

\(\displaystyle 10\)

Correct answer:

\(\displaystyle \small 3. 5\)

Explanation:

To find the median of a data set, we must find the center of the data. If the data set has an odd number of data values, simply subtract one, and then divide in half. Your result will be the amount of values that lie on each side of the median.

However, when there is an even amount of data values, there is no definite center of the data set. The most commonly used method of finding the median given an even amount of data values is to simply cross off data values on either ends of the set until we are left with two numbers in the center:

 \(\displaystyle \small \small \small 2, 2, \textbf{3,4}, 5, 6\). In this set \(\displaystyle \small 3\) and \(\displaystyle \small 4\) are the center numbers.

Now we can find the average of these two values: 

\(\displaystyle \small 3 + 4 = 7, 7\div2 = 3. 5.\) 

Thus, our true center of the data set lies between the numbers \(\displaystyle \small 3\) and \(\displaystyle \small 4\)\(\displaystyle \small 3.5\)

Example Question #51 : How To Find Median

\(\displaystyle \small 23, 42, 53, 22, 55, 12, 56\)

Using the data provided, find the median. 

Possible Answers:

\(\displaystyle \small 42\)

\(\displaystyle \small 22\)

\(\displaystyle \small 53\)

\(\displaystyle \small 22\)

\(\displaystyle \small 56\)

Correct answer:

\(\displaystyle \small 42\)

Explanation:

The median is defined as the center number of the data. To find this value, the first step is to place the numbers in numerical order. 

\(\displaystyle \small 12, 22, 23, 42, 53, 55, 56\).

Since there are 7 pieces of data, and odd number, we can subtract one, and then divide the answer in half. 

\(\displaystyle \small 7- 1 = 6 , 6 \div2 = 3.\) 

This means that the median has to have 3 data values on either side of it.

\(\displaystyle \small 12, 22, 23, {\color{Red} 42}, 53, 55, 56\)

To satisfy this requirement, our median must be \(\displaystyle \small 42.\)

Example Question #44 : Basic Statistics

\(\displaystyle \small 6,6,9,10,15,16,20,30,48\)

Using the data provided, find the median. 

Possible Answers:

\(\displaystyle \small 14\)

\(\displaystyle \small 30\)

\(\displaystyle \small 15\)

\(\displaystyle \small 16\)

Correct answer:

\(\displaystyle \small 15\)

Explanation:

To find the median, we first must put the numbers in numerical order: 

\(\displaystyle \small 6,6,9,10,15,16,20,30,48.\) 

Since there are 9 pieces of data, we subtract one and then divide in half. 

\(\displaystyle \small 9-1 = 8 \div2 = 4\).

This means that there must be 4 pieces of data on either side of the number that is the median.

To satisfy this requirement, \(\displaystyle \small 15\) must be the median. 

Example Question #51 : How To Find Median

\(\displaystyle \small 9,3,1,2,2,1,3\)

Using the data above, find the median. 

Possible Answers:

\(\displaystyle \small 1\)

\(\displaystyle \small 9\)

\(\displaystyle \small 2\)

\(\displaystyle \small 3\)

Correct answer:

\(\displaystyle \small 2\)

Explanation:

The median is the numer that, when put in numerical order, appears in the direct center of the group.

To find this value, we must first put the numbers in numerical order: 

\(\displaystyle \small 1,1,2,2,3,3,9\).

In this set of data we have seven pieces of data, we subtract one, then divide the result in half, 

\(\displaystyle \small 7-1=6\div2 = 3\).

This means that there must be three numbers on either side of the median.

To satisfy this requirement, our median must be \(\displaystyle \small 2\)

Example Question #21 : Median

A P.E. class took the height of every student in inches. These were the results:

\(\displaystyle 48,46,56,53,44,38,39,42,44,47,51,49,60,25\)

Find the median of the class's data set.

Possible Answers:

\(\displaystyle 39\)

\(\displaystyle 38\)

\(\displaystyle 47\)

\(\displaystyle 46\)

\(\displaystyle 46.5\)

Correct answer:

\(\displaystyle 46.5\)

Explanation:

Median means the middle of a sorted set of numbers. That is, it is the exact middle of a set of numbers. 

In order to solve for median, we must allign the numbers in order in increasing value.

\(\displaystyle 48,46,56,53,44,38,39,42,44,47,51,49,60,25\)

This number set will become:

\(\displaystyle 25,38,39,42,44,44,46,47,48,49,51,53,56,60\)

As you cross out one number from each side, you will eventually be left with the remaining number if there is an odd number of numbers. If there is an even number of numbers, the median will be the average of the last two remaining numbers. 

\(\displaystyle {\color{red} 25},38,39,42,44,44,46,47,48,49,51,53,56,{\color{Red} 60}\)\(\displaystyle {\color{Red} 25,38},39,42,44,44,46,47,48,49,51,53,{\color{Red} 56,60}\)\(\displaystyle {\color{Red} 25,38,39,}42,44,44,46,47,48,49,51,{\color{Red} 53,56,60}\)\(\displaystyle {\color{Red} 25,38,39,42},44,44,46,47,48,49{\color{Red},51,53,56,60}\)\(\displaystyle {\color{Red} 25,38,39,42,44},44,46,47,48,{\color{Red} 49,51,53,56,60}\)\(\displaystyle {\color{Red} 25,38,39,42,44,44},46,47,{\color{Red} 48,49,51,53,56,60}\)

Because we're left with two numbers, we must take their mean (average) to solve for the median of the data set.

\(\displaystyle \frac{46+47}{2}=\frac{93}{2}={\color{Blue} 46.5}\)

Example Question #41 : Basic Statistics

Bob recorded the number of hot dogs he ate over the course of the week. On Monday, he ate 13 hot dogs. On Tuesday, he ate 2 hot dogs. On Wednesday, he ate 1 hot dog. On Thursday, he ate 9 hot dogs. On Friday, he ate 12 hot dogs. On Saturday, he ate 9 hot dogs. On Sunday, he ate 3 hot dogs. What was the median number of hot dogs that Bob ate over the course of the week?

Possible Answers:

\(\displaystyle 2\)

\(\displaystyle 12\)

\(\displaystyle 9\)

\(\displaystyle 3\)

Correct answer:

\(\displaystyle 9\)

Explanation:

The median is the middle number of a set of numbers listed in ascending order.

Start by listing out how many hot dogs Bob ate, in ascending order.

\(\displaystyle 1,2,3,9,9,12,13\)

\(\displaystyle 9\) is the number right in the middle of the set, so it must be the median.

Example Question #1 : Mode

Henry has taken a lot of tests this semester in his biology class. In total, he has taken \(\displaystyle 10\) tests. His scores on the tests were \(\displaystyle 89\), \(\displaystyle 88\), \(\displaystyle 88\), \(\displaystyle 100\), \(\displaystyle 75\), \(\displaystyle 88\), \(\displaystyle 78\), \(\displaystyle 91\), \(\displaystyle 92\), \(\displaystyle 82\). What is the mode of all his test scores?

Possible Answers:

\(\displaystyle 89\)

\(\displaystyle 100\)

\(\displaystyle 88\)

\(\displaystyle 75\)

Correct answer:

\(\displaystyle 88\)

Explanation:

The mode is the number that appears most often in a set of numbers.

\(\displaystyle 89, 88, 88, 100, 75, 88, 78, 91, 92, 82\)

If we order our number set we get the following:

\(\displaystyle 75, 78, 82, 88, 88, 88, 89, 91, 92, 100\)

In this case, because Henry scored 88 three times, that is the mode.

Example Question #2 : Mode

Find the mode of the following numbers: 

\(\displaystyle 2,6,3,2,7,10,8,2,6,4\)

Possible Answers:

\(\displaystyle 2\)

\(\displaystyle 8\)

\(\displaystyle 4\)

\(\displaystyle 5\)

\(\displaystyle 6\)

Correct answer:

\(\displaystyle 2\)

Explanation:

The mode is the number that occurs the most in a group.

Rearranging our numbers we get:

\(\displaystyle 2, 2, 2, 3, 4, 6, 6, 7, 8, 10\)

While \(\displaystyle 6\) does occur twice, \(\displaystyle 2\) occurs three times, and no other number does, so \(\displaystyle 2\) must be the mode.

Example Question #3 : Mode

What is the mode of the following number set:

\(\displaystyle 1, 4, 5, 3, 7, 6, 2, 2, 1, 7, 6, 6, 5, 4, 4, 6\)?

Possible Answers:

\(\displaystyle 1\)

\(\displaystyle 6\)

\(\displaystyle 4\)

\(\displaystyle 2\)

\(\displaystyle 7\)

Correct answer:

\(\displaystyle 6\)

Explanation:

The correct answer is 6.

If we reorganize our set in ascending order we get the following:

\(\displaystyle 1, 1, 2, 2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7\)

The mode is the number in a set that appears the most often.

In this particular number set, 6 appears four times and no other number appears more than three times. 

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