18, 1, 24, 18 (Round to the nearest tenth, if necessary.)
A) 20.7
B) 15.3
C) 13.8
D) 15.8
The correct answer and explanation is :
To determine the correct answer, we first find the mean (average) of the given numbers: 18, 1, 24, and 18.
Step 1: Calculate the Sum
[
18 + 1 + 24 + 18 = 61
]
Step 2: Find the Mean
The mean is found by dividing the sum by the number of values:
[
\frac{61}{4} = 15.25
]
Step 3: Round to the Nearest Tenth
Since 15.25 is closest to 15.3 when rounded to the nearest tenth, the correct answer is:
[
\mathbf{B) \ 15.3}
]
Explanation (300 Words)
Finding the mean of a set of numbers is a fundamental concept in statistics and mathematics. The mean represents the central value of a data set and is calculated by summing all the numbers and dividing by the count of numbers. In this problem, the given numbers are 18, 1, 24, and 18.
We start by adding them together:
[
18 + 1 + 24 + 18 = 61
]
Next, we count how many numbers there are: 4. To find the mean, we divide the sum by this count:
[
61 \div 4 = 15.25
]
Rounding to the nearest tenth follows a simple rule:
- If the hundredths digit (second decimal place) is 5 or more, round up.
- If it is less than 5, round down.
In 15.25, the hundredths digit is 5, so we round 15.25 up to 15.3.
Thus, the correct answer is B) 15.3.
Understanding how to calculate and round the mean is useful in real-life applications such as analyzing data in business, finance, and research. It helps summarize large data sets into a single representative number, making it easier to compare different groups or trends over time.