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## What is an observation made by comparing something to a standard?

Measurement is an observation made more specific by comparing some attribute of a system to a standard of reference. An example is when the length of an object is expressed in terms of the length of a meter or when the mass of an object is expressed by referring to a standard such as a gram.

## What is a process used to gather evidence and lead to understanding?

Answer: The process is termed as scientific method.

## What is a statement that a particular event will occur based on reasonable observations of prior events?

Prediction This is a statement that a particular event will occur, based on reasonable observations of prior events.

## What is a scientific conclusion based on much supporting evidence?

Scientific Law. A process used to gather evidence and lead to understanding. Scientific Method. This is a scientific conclusion based on much supporting evidence. Theory.

## What is a particular result of an experiment?

A result of an experiment is called an outcome. The sample space of an experiment is the set of all possible outcomes.

## What is an unwanted influence on a sample?

Bias. This is an unwanted influence on a sample.

## When can you add the variances of two random variables?

Even when we subtract two random variables, we still add their variances; subtracting two variables increases the overall variability in the outcomes.

## How do you add two variances?

The Variance Sum Law- Independent Case If your two sets are independent, like the apples and oranges example, you can use the simplest version of the variance sum law. Var(X ± Y) = Var(X) + Var(Y). This just states that the combined variance (or the differences) is the sum of the individual variances.

## What is the sum of two random variables?

For any two random variables X and Y, the variance of the sum of those variables is equal to the sum of the variances plus twice the covariance.

## How do you combine two means?

A combined mean is a mean of two or more separate groups, and is found by : Calculating the mean of each group, Combining the results….To calculate the combined mean:

1. Multiply column 2 and column 3 for each row,
2. Add up the results from Step 1,
3. Divide the sum from Step 2 by the sum of column 2.

## How do you combine two standard deviations?

The combined standard deviation Sc can be calculated by taking the square root of Sc2. Example: For a group of 50 male workers the mean and standard deviation of their daily wages are 63 dollars and 9 dollars respectively.

## Can you add and subtract standard deviations?

If you will add one standard deviation to your mean and subtract one standard deviation from your mean, you should find that a majority of your scores fall between those two numbers. If you add and subtract 2 standard deviations you should find that nearly all of your scores will fall between those two numbers.

## How do you find the standard deviation between two groups?

Population standard deviation

1. Step 1: Calculate the mean of the data—this is μ in the formula.
2. Step 2: Subtract the mean from each data point.
3. Step 3: Square each deviation to make it positive.
4. Step 4: Add the squared deviations together.
5. Step 5: Divide the sum by the number of data points in the population.

## How do you add mean and standard deviation?

3 Answers. The mean E(X+Y) is equal to the sum of the means E(X) and E(Y), i.e., in your case 2+3.8=5.8. The standard deviation is the square root of the variance Var(X+Y)=Var(X)+Var(Y)+2Cov(X,Y). The standard deviation is calculated differently if your sample correspond to the whole population or not.

## What is the relation between mean and standard deviation?

Standard deviation and Mean both the term used in statistics. Standard deviation is statistics that basically measure the distance from the mean, and calculated as the square root of variance by determination between each data point relative to the mean.

2021-05-15