Measurement, Errors, Data and Unit Conversion

If 1 ft is 0.305 m, ten of them would be 3.05 m and 20 of them would be as shown in choice D.

B is also correct but is not as good an answer as choice C.

Median is the midpoint of the number of measured values. The value that appears most often in a set of data is called the mode.

Scientific notation requires one number to the right of the decimal point (choices B and C). The decimal point must be shifted two places to achieve this. As 0.028 is less than one, the power of 10 is negative.

The absolute error is plus or minus half of the smallest scale interval (this means that the maximum error is this, but the actual error may be less). The interval is 5 ml, so 2.5 ml is half of this and equal to the absolute error.

Pascal (Pa) is the SI unit for pressure.

“Milli” refers to thousandth or 10−3 (nothing to do with million!).

The median is the middle number. Half of the ten numbers are larger than (or equal to) the median and half are smaller. The wages have been arranged in ascending order: the fifth is $500 and the sixth is also $500. So half of the numbers are $500 or less and half are $500 or more. The median is midway between these two numbers and is $500.

This is the only true statement for normally distrusted data.

Any zero to the left of the first non-zero digit – when approached from the left – are not significant (zeros on the right are).