Find the mean (up to 2 decimal points) of the following numbers:
8.9, 6.5, 7.8, 12.3, 15.6, 14.4, 9.8

Options

A. 8.96
B. 7.85
C. 9.83
D. 10.76

Answer

To find the mean of the given numbers: 8.9, 6.5, 7.8, 12.3, 15.6, 14.4, and 9.8, we will follow these steps:

### Step 1: List the numbers
The numbers we have are:
- 8.9
- 6.5
- 7.8
- 12.3
- 15.6
- 14.4
- 9.8

### Step 2: Calculate the sum of the numbers
We will add all the numbers together:
\[ 8.9 + 6.5 + 7.8 + 12.3 + 15.6 + 14.4 + 9.8 \]

Calculating step by step:
- \(8.9 + 6.5 = 15.4\)
- \(15.4 + 7.8 = 23.2\)
- \(23.2 + 12.3 = 35.5\)
- \(35.5 + 15.6 = 51.1\)
- \(51.1 + 14.4 = 65.5\)
- \(65.5 + 9.8 = 75.3\)

So, the sum of the numbers is \(75.3\).

### Step 3: Count the number of observations
We have a total of 7 numbers.

### Step 4: Calculate the mean
The mean is calculated using the formula:
\[ \text{Mean} = \frac{\text{Sum of observations}}{\text{Number of observations}} = \frac{75.3}{7} \]

Calculating the mean:
\[ \frac{75.3}{7} \approx 10.7571428571 \]

### Step 5: Round the mean to two decimal points
Rounding \(10.7571428571\) to two decimal points gives us \(10.76\).

### Final Answer
The mean of the given numbers is \(10.76\).

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