the mean

the mode

the range

the median

has a true zero point

uses seven intervals with the equal distance between the intervals

indicates quantities such as more or less

has equal intervals between the points on the scale

9

6.1

6.5

6

nothing useful.

an arbitrary level of happiness.

low levels of happiness.

an absence of happiness.

negatively

symmetrically 

normally 

positively 

football numbers

mailbox numbers

Celsius temperature scale

IQ scores

The mean will stay the same.

The mean will decrease.

The mean will be larger than the median and the mode. 

The mean will increase.

it varies less from sample to sample.

it is easier to calculate than the mode.

it is usually closer to the population mean than the mode.

it is not much affected by extreme scores.

adrenaline 

distance from the airport 

location 

stress 

both scales cary the same level of information. 

with an interval scale you know which values represent more of the quantity

with an interval scale you cam speak meaningfully about a score of 0.

with a ratio scale you can speak meaningfully about a score of 0.