Algebra 1 : Independent work:Geometry Preview

Segment Addition:

View Video: Number and Algebra in Deltamath

https://www.educreations.com/lesson/view/line-segment-addition-postulate/54764855/?s=Z4H6el&ref=link

Assignment:

Algebra 1- The Segment Addition Postulate

Suppose XA = 3x and AY =  4x - 6. If A is the midpoint of XY, what is the length of XY?

           3x                       4x - 6
_________________________________
X                         A                         Y

The trick in this problem is to see that if A is the midpoint, then XA = AY.

Since XA = AY, 3x = 4x - 6

Subtract 3x from both sides.

3x - 3x = 4x - 3x - 6

0  = x - 6

Add 6 to both sides of the equation.

0 + 6 = x - 6 + 6

6 = x

To compute XA, you can either use 3x or 4x - 6

Using 3x, we get XA = AY = 3 × 6 = 16

Using 4x - 6, we get XA = AY = 3 × 6 - 6 = 18 - 6 = 12

XY = XA + AY = 16 + 16 = 32

The length of XY is 32.

Source:https://www.basic-mathematics.com/segment-addition-postulate.html

Assignment: 

Instructional Video 5/5

Algebra 1- Joint and marginal frequency tables re-teaching

Good afternoon,
Since we struggled with this concept, I will be reteaching it today.
See you at the zoom call!

Algebra 1- Joint and marginal frequency tables

Relative Frequency

How often something happens divided by all outcomes.

Example: Your team has won 9 games from a total of 12 games played:

• the Frequency of winning is 9
• the Relative Frequency of winning is 9/12 = 75%

All the Relative Frequencies add up to 1 (except for any rounding error).

Example: Travel Survey

92 people were asked how they got to work:

• 35 used a car
• 42 took public transport
• 8 rode a bicycle
• 7 walked

The Relative Frequencies (to 2 decimal places) are:

• Car: 35/92 = 0.38
• Public Transport: 42/92 = 0.46
• Bicycle: 8/92 = 0.09
• Walking: 7/92 = 0.08

0.38+0.46+0.09+0.08 = 1.01

(It would be exactly 1 if we had used perfect accuracy)

Source:https://www.mathsisfun.com/data/relative-frequency.html

Assignment

 Each student in a random sample of students at a local high school was categorized according to gender (male or female) and whether they supported a proposal to increase the length of the school day by 30 minutes (oppose, support, no opinion). The following table summarizes the data for this sample.

		Opinion on Proposal to Increase Length of School Day
		Oppose	Support	No Opinion	Total
Gender	Male	50	40	20	110
	Female	40	40	10	90
	Total	90	80	30	200

a.             What proportion of the students in this sample are male?
 

b.             What proportion of the students in this sample support the proposal?
 

c.              What proportion of the males in this sample support the proposal?
 

d. What proportion of the students in this sample who support this proposal are female?

Algebra 1 Instructional video 4/30

2 way table

Two-Way Table

Do you believe in Martians? Here is a survey of 100 college students asking that very question: Do you believe in Martians?

Gender	Yes	No
Male	10	32
Female	38	20
Total	48	52

This type of table is called a two-way or contingency table.

A two-way or contingency table is a statistical table that shows the observed number or frequency for two variables, the rows indicating one category and the columns indicating the other category. The row category in this example is gender - male or female. The column category is their choice, yes or no.

There is a lot of information we can learn from this small table. Let's look at a couple questions you could see on a test.

How many males were asked? Let's look across the male row. Ten said 'yes' and 32 said 'no.' That would be a total of 42 males.

How many college students believe in Martians? Look down the Yes column. Ten males and 38 females said 'yes.' That would be a total of 48 college students.

Example #2

A recent survey of 100 college students asked if they prefer to drink tea, coffee, or an energy drink during finals week. Here is the table created from that survey.

Gender	Tea	Coffee	Energy Drink
Male	2	15	39
Female	18	20	6
Total	20	35	45

Let's look at a couple questions you could see on a test.

How many college students drink tea given that they are a female? In this question, we're looking for tea drinkers that are female. Let's look at the female row and tea column. The answer is 18.

How many students drink tea or are male? In this question, we're looking for all tea drinkers united with all males. To figure out the answer, let's highlight the Tea column and Male row. We do have an overlap at Tea and Male, so be sure not to add that twice. So our answer is Total Tea drinkers 20 plus Total Males 56 minus the overlap of 2. 20 + 56 - 2 = 74. There are 74 students that are tea drinkers or male.

Source:https://study.com/academy/lesson/what-is-a-two-way-table.html

Assignment: quizziz code: 898765