Question

rounding
5 - 9 = round ↑
0 - 4 = round ↓
practice rounding
whole number
20.5
9.87
8.06
1.21
0.74
18.99
33
find the mean for each data set:
round to nearest whole num
1, 2, 3, 4, 5
5, 9, 3, 10, 2
2, 2, 2

Explanation:

Step1: Recall rounding rules

If the digit after the decimal is 5 - 9, round up; if 0 - 4, round down.

Step2: Round 20.5

The digit after the decimal is 5, so round up to 21.

Step3: Round 9.87

The digit after the decimal is 8 (in the tenths - place), so round up to 10.

Step4: Round 8.06

The digit after the decimal is 0, so round down to 8.

Step5: Round 1.21

The digit after the decimal is 2, so round down to 1.

Step6: Round 0.74

The digit after the decimal is 7, so round up to 1.

Step7: Round 18.99

The digit after the decimal is 9, so round up to 19.

Step8: Round 33

33 is already a whole number, so it remains 33.

Answer:

Original Number	Rounded Whole - Number
9.87	10
8.06	8
1.21	1
0.74	1
18.99	19
33	33

Now, for finding the mean of data - sets and rounding to the nearest whole number:

Step1: Calculate the mean of 1, 2, 3, 4, 5

The mean formula is $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 5$ and $\sum_{i=1}^{5}x_{i}=1 + 2+3 + 4+5=15$. So, $\bar{x}=\frac{15}{5}=3$.

Step2: Calculate the mean of 5, 9, 3, 10, 2

$\sum_{i = 1}^{5}x_{i}=5 + 9+3 + 10+2=29$, and $n = 5$. So, $\bar{x}=\frac{29}{5}=5.8$, which rounds up to 6.

Step3: Calculate the mean of 2, 2, 2

$\sum_{i = 1}^{3}x_{i}=2 + 2+2=6$, and $n = 3$. So, $\bar{x}=\frac{6}{3}=2$.