Measures of Central Tendency Review

1, 5, 6, 10, 7, 2, 2, 6, 2, 5 Data Set in Order: Sum of the Numbers: Mean: Median: Mode: Range:

5, 5, 6, 9, 4, 3, 4, 8, 10, 4 Data Set in Order: Sum of the Numbers: Mean: Median: Mode: Range:

125000, 126500, 131500, 142000, 120500 Data Set in Order: Sum of the Numbers: Mean: Median: Mode: Range:

5.6, 5.7, 5.4, 5.9, 6.0, 5.8 Data Set in Order: Sum of the Numbers: Mean: Median: Mode: Range:

28, 35, 50, 56, 88, 63, 35, 72, 84, 88 Data Set in Order: Sum of the Numbers: Mean: Median: Mode: Range:

Intro to Agriculture AAEC – PV Fall 2014 The Metric System Intro to Agriculture AAEC – PV Fall 2014

The International System of Units If everyone is to understand what your measurements mean, you must agree on the units that will be used. By international agreement, a set of units called "The International System of Units" has been defined for scientific work. This system was adopted in 1960 by the General Conference on Weights and Measures. These units are also called metric units or SI units.

SI has Eight base units Quantity Unit Name Unit Abbreviation Length meter m Mass gram g Time second s or sec Temperature Kelvin K Volume Liter L Amount of Substance mole mol Electric Current ampere A Energy Joules J

Advantages of Using SI Units SI Units make measuring and calculating easier. Measurements are always expressed as decimals rather than fractions. It is very easy to change from one unit to another since they are based on 10. It is universally understood.

SI Prefixes Prefixes can be placed in front of the base units. These prefixes are used to represent quantities that are larger or smaller than the base units. Prefix Unit Abbreviation Meaning giga G 1,000,000,000 mega M 1,000,000 kilo k 1,000 hecto h 100 deca da 10 1 deci d .1 centi c .01 milli m .001 micro  .000001 nano n .000000001

How many meters are in each of the following? 1 Gm = ? m 1 Mm = ? m 1 km = ? m 1 hm = ? m 1 dam = ? m ? dm = 1 m ? cm = 1 m ? mm = 1 m ?  m = 1 m ? nm = 1 m 1,000,000,000 m 1,000,000 m 1,000 m 100 m 10 m 10 dm 100 cm 1,000 mm 1,000,000 m 1,000,000,000 nm

Metric Unit of Length The meter (m) is the SI base unit of length. Prefixes are used to indicate distances longer and shorter than a meter. What name and symbol is given to each of the following units of length? .000001 m .001 m .01 m .1 m 10 m 1000 m Micrometer m Millimeter mm Centimeter cm Decimeter dm Decameter dam Kilometer km

Metric Unit of Volume Volume: the space occupied by a sample of matter The cubic meter (m3) is the SI derived unit for measuring volume. When chemists measure the volumes of liquids and gases, they often use a non-SI unit called the liter. The two units, mL and cm3, are interchangeable.

Metric Unit of Mass Mass: the amount of matter within an object Weight: the measure of gravitational pull on an object Mass and weight are often confused. Mass is not affected by gravitational pull. The kilogram is the SI base unit for measuring mass.

Dimensional Analysis Dimensional Analysis: a process used to convert between units. “Conversion factors” are numbers that are used to change from one unit to another. Conversion factors are formed from equalities that state a relationship between two units. For example: 1 kilometer = 1000 meters When conversion factors are used properly, all units will divide out (or cancel out) EXCEPT the unit being converted to.

Solving a Problem Using Dimensional Analysis How many kilometers are equal to 250 meters? 250 m 1 kilometer = .250 km 1000 meters When solving a problem using dimensional analysis, start with what you are given in the problem. Decide what conversion factor should be used in the next step. In the conversion factor step, place the unit on bottom that will cancel the unit in the previous step. Proceed until you are left with the unit you are looking for.

Convert .044 km to meters Convert 4.6 mg to grams. .044 km 1000 m

How many seconds are in .079 years? Convert 696 cm3 to m3 696 cm3 (1)3 m3 = .000696 m3 (100)3 cm3 How many seconds are in .079 years? .079 yr 365 days 24 hr 60 min 60 sec 1 yr 1 day 1 hr 1 min = 2,491,344 sec

Convert .065 km to dm .065 km 1000m 10 dm = 650 dm 1 km 1 m The density of manganese is 7.21 g/cm3. What is the density in kg/m3? 7.21 g cm3 1 kg (100)3 cm3 = 7210 kg/m3 1000 g (1)3m3

Convert 0.44 mL/min to microliters/sec   0.44 mL min 1 L 1,000,000 L 1 min = 7.33 L/sec 1000 mL 1 L 60 sec There are 7 x 106 red blood cells in 1.0 mm3 of blood. How many red blood cells are in one liter of blood? 7 x 106 cells (1000)3 mm3 (1)3 m3 1 cm3 1000 mL   1.0 mm3 (1)3 m3 (100)3 cm3 1 mL 1 L = 7 x 1012 cells/L