Interval scales have measurements which are in equal distance from each other. For example, the difference between 70 degrees and 80 degrees is 10, which is the same as the difference between 40 degrees and 50 degrees. Ratio scales are similar to interval scales but include an absolute 0 measurement, which signifies the point when the characteristic being measured vanishes. For example, income (measured in dollars) at 0 means no income at all. Basically, interval and ratio scales are the same, but ratio scales must be able to be measured at a zero starting point.
Interval scales have measurements which are an equal distance from each other. For example, the difference between a temperature of 70 degrees and 80 degrees is 10, which is the same as the difference between 40 degrees and 50 degrees. Ratio scales are similar to interval scales but include an absolute 0 measurement, which signifies the point when the characteristic being measured vanishes. What this also means is that 3 feet is 3/2 times as far as 2 feet. The ratio of the values is maintained. This latter quality is not maintained in the temperature scales in common use: 5 deg C is not half as warm as 10 deg C (or degrees Fahrenheit, for that matter). THat only works with the absolute temperature scale = Kelvin.
Ratio. All pressure readings are on the ratio scale. There is a starting point, atmospheric pressure. If there blood pressure increases by 10%, there is 10% more force being exerted. I note a related one - temperature is a tricky one. If I have degrees C, then it is on the interval scale, but if I convert to degrees K, then it can be considered on the ratio scale, as there is a starting point, and a doubling K has meaning. I'M NEW, AND DID NOT WANT TO REMOVE THE FIRST ANSWER, BUT I AM CERTAIN IT IS INCORRECT. HERE IS WHY: Actually, the scale is INTERVAL, because of the above-mentioned fact that the starting point is the atmospheric pressure. Atmospheric pressure is not an absolute zero point. Say you are at the sea level, where normal air pressure is 1 atm=101.325kPa=760mmHg (millimeters of mercury are usually used to report blood pressure), and your Systolic Blood Pressure is 68mmHg (so the absolute value is: 760mmHg of starting point + 68mmHg of your blood pressure = 828mmHg). Now, let's say your Systolic Blood Pressure jumped 10%, that is to 74.8mmHg (the new absolute value is: 760mmHg of the same starting point + 74.8mmHg of your new blood pressure = 834.8mmHg), and the absolute ratio is not maintained, i.e.: 834.8mmHg / 828mmHg = 1.008. That is the absolute increase is about 0.8%. The differences become even more significant at higher elevations, where the air pressure is lower.
interval
ratio
Interval scales have measurements which are in equal distance from each other. For example, the difference between 70 degrees and 80 degrees is 10, which is the same as the difference between 40 degrees and 50 degrees. Ratio scales are similar to interval scales but include an absolute 0 measurement, which signifies the point when the characteristic being measured vanishes. For example, income (measured in dollars) at 0 means no income at all. Basically, interval and ratio scales are the same, but ratio scales must be able to be measured at a zero starting point.
A variable measured at the interval or ratio level can have more than one arithmetic mean.
Temperature is typically measured on an interval scale, as it has equal intervals between each level but does not have a true zero point. However, in some contexts (such as in Kelvin scale), temperature can be considered a ratio scale where absolute zero represents a true zero point.
histogram
Interval scales have measurements which are an equal distance from each other. For example, the difference between a temperature of 70 degrees and 80 degrees is 10, which is the same as the difference between 40 degrees and 50 degrees. Ratio scales are similar to interval scales but include an absolute 0 measurement, which signifies the point when the characteristic being measured vanishes. What this also means is that 3 feet is 3/2 times as far as 2 feet. The ratio of the values is maintained. This latter quality is not maintained in the temperature scales in common use: 5 deg C is not half as warm as 10 deg C (or degrees Fahrenheit, for that matter). THat only works with the absolute temperature scale = Kelvin.
Ratio. All pressure readings are on the ratio scale. There is a starting point, atmospheric pressure. If there blood pressure increases by 10%, there is 10% more force being exerted. I note a related one - temperature is a tricky one. If I have degrees C, then it is on the interval scale, but if I convert to degrees K, then it can be considered on the ratio scale, as there is a starting point, and a doubling K has meaning. I'M NEW, AND DID NOT WANT TO REMOVE THE FIRST ANSWER, BUT I AM CERTAIN IT IS INCORRECT. HERE IS WHY: Actually, the scale is INTERVAL, because of the above-mentioned fact that the starting point is the atmospheric pressure. Atmospheric pressure is not an absolute zero point. Say you are at the sea level, where normal air pressure is 1 atm=101.325kPa=760mmHg (millimeters of mercury are usually used to report blood pressure), and your Systolic Blood Pressure is 68mmHg (so the absolute value is: 760mmHg of starting point + 68mmHg of your blood pressure = 828mmHg). Now, let's say your Systolic Blood Pressure jumped 10%, that is to 74.8mmHg (the new absolute value is: 760mmHg of the same starting point + 74.8mmHg of your new blood pressure = 834.8mmHg), and the absolute ratio is not maintained, i.e.: 834.8mmHg / 828mmHg = 1.008. That is the absolute increase is about 0.8%. The differences become even more significant at higher elevations, where the air pressure is lower.
It is ratio.
interval
The coefficient of variation should be computed only for data measured on a ratio scale, as the coefficient of variation may not have any meaning for data on an interval scale. Using relative values instead of absolute values can cause the formula to give an incorrect answer.
Sampling Interval is the inverse of sampling ratio. For instance, we want to sample 300 names from 900. After a random starting point, we select every third name of the 900 to get a sample of 300. The sampling ratio is 300/900 = 0.333 (or 33%) and the sampling interval is 1/0.333 which is 3.
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ratio