SSAT Middle Level Quantitative - How to find mean

Give the mean of the data set (nearest tenth, if applicable):

$\left { 56,78,98,85,77,73 \right }$

Explanation

Add the six elements and divide the sum by 6:

$467 \div 6 \approx 77.8$

Find the mean of the following set of numbers:

46.7

54.5

40.9

Explanation

The mean is equal to the sum of the values divided by the total number of values.

$mean=\frac{34+56+73+43+80+15+26}{7}=46.7$

Find the mean in this set of numbers:

Explanation

First, add all the numbers in this set:

Then, divide by 5:

$2970 \div 5=594$

Answer: The mean is 594.

What is the mean of the following numbers?

Explanation

The mean is determined by calculating the sum of all values divided by the total number of values:
$mean=\frac{\sum_n}{n}=\frac{14+22+12+11+13+6}{6}=\frac{78}{6}=13$

Give the median of the following eight scores:

$\left { 61, 67, 80, 72, 76, 73, 90, 68 \right }$

Explanation

Arrange the scores from least to greatest.

$\left { 61, 67, 68, 72, 73, 76, 80, 90 \right }$

There are an even number (eight) of scores, so the median is the arithmetic mean of the middle two scores, 72 and 73. This makes the median

$\frac{72 + 73}{2} = 72.5$

In a group of 4 books, the average number of pages is is 10. Juan adds a book with 20 pages to the group. What is the new average number of pages?

Explanation

If the average of 4 books was 10, then the total number of pages was $4\times10 =40$ . Adding in the 20 new pages, but now dividing by 5 you get .

Find the mean of this set of numbers:

5855, 5588, 5585, 5858, 5885, 5559, 5885

Explanation

First, add the numbers in the set:

Then, divide by the amount of numbers in the set:

$40215\div 7=5745$

Answer: The mean is 5745.

Patricia is shopping for a coat. She is considering three coats. Each costs $85.98, $93.29 and $88.99, respectively. What is the average price of a coat she is considering?

Explanation

First, add up all of the prices:

Then, divide $268.26 \div 3= 89.42$ .

Answer: The average price of a coat is $89.42.

In Maria's family, her parents are both 45 years old, and her younger brother is 2 years younger than she is. What is the mean of their ages, if Maria is 5 years old?

Explanation

The mean of a set is found by finding the sum of the set and then dividing by the number of items in the set. Given that both of her parents are 45 years old, that Maria is 5 years old, and that her brother is 3 years old (being 2 years younger than she is), the mean is calculated using this equation:

$\frac{45+45+5+3}{4}=24.5$