The mean of 30 observations recorded in an experiment is 4. If the largest value of the 30 observations is deleted, find the mean of the remaining distribution.



Answer :

To solve this question, let's carefully follow these steps:

1. Determine the total sum of all 30 observations.

We know that the mean (average) of 30 observations is 4. The formula for the mean is:

[tex]\[ \text{Mean} = \frac{\text{Sum of all observations}}{\text{Number of observations}} \][/tex]

Rearranging this formula to find the total sum of the observations gives us:

[tex]\[ \text{Sum of all observations} = \text{Mean} \times \text{Number of observations} \][/tex]

Given the mean is 4 and the number of observations is 30, we get:

[tex]\[ \text{Sum of all observations} = 4 \times 30 = 120 \][/tex]

2. Assume the value of the largest observation.

Let's denote the value of the largest observation as [tex]\( L \)[/tex]. This value needs to be provided or hypothesized.

3. Subtract the largest observation from the total sum.

Once the largest observation [tex]\( L \)[/tex] is removed, the new sum of the remaining 29 observations is:

[tex]\[ \text{New sum} = 120 - L \][/tex]

4. Determine the number of remaining observations.

Since we have removed one observation, the number of remaining observations is:

[tex]\[ 30 - 1 = 29 \][/tex]

5. Calculate the new mean.

The new mean of the remaining 29 observations can be determined using the formula for the mean:

[tex]\[ \text{New mean} = \frac{\text{New sum}}{\text{Number of remaining observations}} \][/tex]

Plugging in the values we have:

[tex]\[ \text{New mean} = \frac{120 - L}{29} \][/tex]

6. Conclusion:

The new mean of the remaining distribution, after removing the largest observation, is given by:

[tex]\[ \text{New mean} = \frac{120 - L}{29} \][/tex]

To find the exact numerical value of the new mean, you would need to know or be given the specific value of the largest observation [tex]\( L \)[/tex].