Knowee
Questions
Features
Study Tools

The mean and sample standard deviation of the dataset consisting of 10 observations is 16 and 10 respectively. Later it is noted that one observation 16 is wrongly noted as 10. What is the sample variance of the original dataset? (Correct to 2 decimal place accuracy)

Question

The mean and sample standard deviation of the dataset consisting of 10 observations is 16 and 10 respectively. Later it is noted that one observation 16 is wrongly noted as 10. What is the sample variance of the original dataset? (Correct to 2 decimal place accuracy)

🧐 Not the exact question you are looking for?Go ask a question

Solution

Step 1: Calculate the sum of the dataset

The sum of the dataset can be calculated by multiplying the mean by the number of observations.

So, Sum = Mean * Number of observations = 16 * 10 = 160

Step 2: Correct the error in the dataset

The sum of the dataset after correcting the error is the original sum minus the incorrect observation plus the correct observation.

So, Corrected Sum = Original Sum - Incorrect observation + Correct observation = 160 - 10 + 16 = 166

Step 3: Calculate the corrected mean

The corrected mean is the corrected sum divided by the number of observations.

So, Corrected Mean = Corrected Sum / Number of observations = 166 / 10 = 16.6

Step 4: Calculate the sum of squares of the dataset

The sum of squares of the dataset can be calculated by adding the square of the standard deviation to the square of the mean, multiplied by the number of observations.

So, Sum of squares = (Standard deviation)^2 * Number of observations + Mean^2 * Number of observations = 10^2 * 10 + 16^2 * 10 = 1000 + 2560 = 3560

Step 5: Calculate the corrected sum of squares

The corrected sum of squares is the original sum of squares minus the square of the incorrect observation plus the square of the correct observation.

So, Corrected Sum of squares = Original Sum of squares - Incorrect observation^2 + Correct observation^2 = 3560 - 10^2 + 16^2 = 3560 - 100 + 256 = 3716

Step 6: Calculate the sample variance

The sample variance is the corrected sum of squares divided by the number of observations minus 1, minus the square of the corrected mean.

So, Sample Variance = (Corrected Sum of squares / (Number of observations - 1)) - Corrected Mean^2 = (3716 / (10 - 1)) - 16.6^2 = 412.89 - 275.56 = 137.33

So, the sample variance of the original dataset is 137.33 (correct to 2 decimal places).

This problem has been solved

Similar Questions

Consider a sample with data values of 10, 20, 12, 17, and 16. Compute the variance and standarddeviation.

Consider the following dataset: 9, 12, 15, 18, 21. What is the standard deviation of this dataset?a.3.6b.4c.4.24d.5.5

STANDARD DEVIATION A data set contains the following values: 11, 3, 5, 18, 1, 4, 7. Find the population variance. Round your answer to 4 decimal places.

For the data set 6, 5, 10, 11, 13, the mean, x, is 9. What is the standard deviation?The formula for the sample standard deviation is 𝑠=1𝑛−1Σ(𝑥−𝑥ˉ)2s= n−11​ Σ(x− xˉ ) 2 ​ .Use the table to help you.Round your answer to the nearest tenth.

Calculate the standard deviation of the sample quantitative data shown, to two decimal places. x 5 10.6 2 24.7 22.3 18.9 Standard deviation:

1/3

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.