1. The table shows the frequency distribution of a dataset:

| data (x) | 1 | 2 | 3 | 4 | 5 |
|:---------:|:-----:|:-----:|:-----:|:-----:|:-----:|
| frequency (F) | x+2 | x-1 | x-3 | x+4 | 3x-4 |

If the mean is [tex]$\frac{43}{4}$[/tex], find the value of [tex]$x$[/tex].



Answer :

To find the value of [tex]\(x\)[/tex] given the data and their frequencies, and knowing that the mean is [tex]\(\frac{43}{4}\)[/tex], we first write down the information:

### Data and Frequencies:
- Data: [tex]\(\{1, 2, 3, 4, 5\}\)[/tex]
- Frequencies: [tex]\(\{x+2, x-1, x-3, x+4, 3x-4\}\)[/tex]

### Mean Calculation:
The formula for the weighted mean is given by:
[tex]\[ \bar{x} = \frac{\sum (data_i \times Frequency_i)}{\sum Frequency_i} \][/tex]

Given the mean:
[tex]\[ \bar{x} = \frac{43}{4} \][/tex]

### Step-by-Step Solution:
1. Calculate the sum of frequencies:
[tex]\[ \sum Frequency_i = (x + 2) + (x - 1) + (x - 3) + (x + 4) + (3x - 4) \][/tex]
Combine like terms:
[tex]\[ \sum Frequency_i = x + 2 + x - 1 + x - 3 + x + 4 + 3x - 4 = 7x - 2 \][/tex]

2. Calculate the sum of the product of data and frequencies:
[tex]\[ \sum (data_i \times Frequency_i) = 1(x+2) + 2(x-1) + 3(x-3) + 4(x+4) + 5(3x-4) \][/tex]
Expand each term:
[tex]\[ 1(x + 2) = x + 2 \][/tex]
[tex]\[ 2(x - 1) = 2x - 2 \][/tex]
[tex]\[ 3(x - 3) = 3x - 9 \][/tex]
[tex]\[ 4(x + 4) = 4x + 16 \][/tex]
[tex]\[ 5(3x - 4) = 15x - 20 \][/tex]

Sum these expressions:
[tex]\[ x + 2 + 2x - 2 + 3x - 9 + 4x + 16 + 15x - 20 = 25x - 13 \][/tex]

3. Set up the mean equation:
[tex]\[ \frac{25x - 13}{7x - 2} = \frac{43}{4} \][/tex]

4. Cross-multiply to solve for [tex]\(x\)[/tex]:
[tex]\[ 4(25x - 13) = 43(7x - 2) \][/tex]
Expand both sides:
[tex]\[ 100x - 52 = 301x - 86 \][/tex]

5. Isolate [tex]\(x\)[/tex]:
[tex]\[ 100x - 301x = -86 + 52 \][/tex]
Combine like terms:
[tex]\[ -201x = -34 \][/tex]
Divide both sides by -201:
[tex]\[ x = \frac{34}{201} \][/tex]

So, the value of [tex]\(x\)[/tex] that satisfies the given conditions is:
[tex]\[ x = \frac{34}{201} \][/tex]

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