## Wednesday, January 21, 2009

### scribe post for jan 21, 2009

Today we did math link page 437-439 1-16

We have a Quiz tommorow jan 22 2009 its about decimals/fraction/percents/mean/median/mode/range/outlier

Decimals-A linear array of digits that represents a real number, every decimal place indicating a multiple of a negative power of 10. For example, the decimal 0.1 = 1/10 , 0.12 = 12/100 , 0.003 = 3/1000 . Also called decimal fraction.

Fraction- a number expressed as a quotient, in which a numerator is divided by a denominator. In a simple fraction, both are integers. A complex fraction has a fraction in the numerator or denominator. In a proper fraction, the numerator is less than the denominator. If the numerator is greater, it is called an improper fraction and can also be written as a mixed number — a whole-number quotient with a proper-fraction remainder. Any fraction can be written in decimal form by carrying out the division of the numerator by the denominator. The result may end at some point, or one or more digits may repeat without end.

Percent-, a quantity can be increased by any percentage but cannot be decreased by more than 100 percent. Once pollution has been reduced by 100 percent, for example, it ceases to exist. In defiance of this logic, however, advertisers sometimes refer to a 150 percent decrease in lost luggage or a new dental rinse that reduces plaque on teeth by over 300 percent. Presumably what is implied by the latter is that the new rinse is three times as effective as some other rinse, but such constructions are still subject to criticism as illogical.·Percent can take a singular or plural verb, depending on how the quantity being described is viewed. Very often what determines the form of the verb is the noun nearest to it. Thus one might say Eighty percent of the legislators are going to vote against the bill or Eighty percent of the legislature is set to vote the bill down. In the second sentence the group of legislators is considered as a body, not as individuals. When percent is used without a following prepositional phrase, either a singular or plural verb is acceptable.

Measures Of Central Tendancy

mean- The MEAN is the arithmetic average, the average you are probably used to finding for a set of numbers - add up the numbers and divide by how many there are:Eg(80 + 90 + 90 + 100 + 85 + 90) / 6 = 89 1/6.

mode-The mode of a set of numbers is the one that occurs most often. So, in the set {1,5,7,5,9}, the mode is 5 because there are 2 fives and only one of each of the others.Now here is a problem for you: Find the mode of this set of numbers:
2 6 9 0 5 2 4 1 6 4 5 2

median- Median is the middle value of the given numbers or distribution in their ascending order.Median is the average value of the two middle elements when the size of the distribution is even.

Range-Example 1:
The Jaeger family drove through 6 midwestern states on their summer vacation. Gasoline prices varied from state to state. What is the range of gasoline prices?

\$1.79, \$1.61, \$1.96, \$2.09, \$1.84, \$1.75
Solution:
Ordering the data from least to greatest, we get:

\$1.61, \$1.75, \$1.79, \$1.84, \$1.96, \$2.09

highest - lowest = \$2.09 - \$1.61 = \$0.48
The range of gasoline prices is \$0.48.

Outliers- For a set of numerical data, any value that is markedly smaller or larger than other values. For example, in the data set {3, 5, 4, 4, 6, 2, 25, 5, 6, 2} the value of 25 is an outlier.

I PICK BRENDAN