How does accuracy differ from precision?
Accuracy is how close a measurement is to a generally accepted value. Precision is how many digits the measurement is.
My weight is 160 lbs, generally accepted as true.
My to scales recoreded my weight as 164lbs, and as 144.432 lbs.
The most accurate was 164, but the most precise was the 144.432 lbs.
what about
Why must a calculated answear generally be rounded? and how many siginificant figures must you round an answear to when performing multiplication or division?
A calculated answer must generally be rounded because it's often impossible to have an exact value due to limitations in the precision of measurements or the mathematical calculations involved. Rounding helps to provide a more practical representation of the answer.
When performing multiplication or division, the rule for rounding to the appropriate number of significant figures is as follows:
- For multiplication and division, count the number of significant figures in each factor or divisor, and round the answer to the same number of significant figures as the factor or divisor with the least number of significant figures.
For example, let's say you perform the following multiplication calculation:
3.25 x 2.87 = 9.3275
In this case, the number 3.25 has three significant figures, and the number 2.87 has three significant figures as well. Since 2.87 has the least number of significant figures, you should round the answer to three significant figures:
9.33
So, in multiplication or division, you generally round the answer to the same number of significant figures as the factor or divisor with the least number of significant figures.