Please help me Answer the encircled numbers only

lbvjy [14]

If a×b÷2=a÷2 then b = 1

8 0

2 years ago

Alex has a collection of sports cards. There are 10 cards in the collection, and 1/5 of them are hockey cards. Alex decides to d

Alborosie

If 1/5 of the cards are hockey cards, there are 2 hockey cards. if he wants to double that amount, he would multiply it by 2, so 2•2=4. The fraction of hockey cards is now is 2/5.

4 0

2 years ago

Wendy wants to put a wallpaper border around her bedroom. The room has two walls that each measure 10 feet 5

cestrela7 [59]

Answer:

11 yards

Step-by-step explanation:

The room has two sides both measuring 10 feet 5 inches. This gives a total of 20 feet 10 inches. It also has the other two sides both measuring 6 feet 1 inch and that too gives a total of 12 feet 2 inches. Adding them all together results in 32 feet 12 inches. Better still, the perimeter of the room is derived as;

Perimeter = 2 (L + W)

Perimeter = 2 (10'5" + 6'1")

Perimeter = 2(16'6")

Perimeter = 32'12"

Having in mind our conversion rate of 12 inches equals 1 foot, the results can be properly expressed as 32 feet plus 1 foot which gives us 33 feet.

If the perimeter of Wendy's room is now given as 33 feet, the conversion rate between feet and yards can now be applied. Having been given that

3 feet = 1 yard

Then 1 yard = 3 feet/3, that is

y = 3/3

Hence,

y = 33/3

y = 11

The results show that Wendy would needs to buy a total of 11 yards of wallpaper border.

3 0

3 years ago

What is the value of this expression when d equals three

kotykmax [81]

Answer:

What is the expresion I am confused?

Step-by-step explanation:

8 0

3 years ago

Listed below are the numbers of heroic firefighters who lost their lives in the United States each year while fighting forest fi

Marysya12 [62]

Answer:

Step-by-step explanation:

Hello!

Data

Year/Firefighters

2000: 20

2001: 18

2002: 23

2003: 30

2004: 20

2005: 12

2006: 24

2007: 9

2008: 25

2009: 15

2010: 8

2011: 11

2012: 15

2013: 34

Common measures of variation

Variance

S²= $\frac{1}{n-1}[sumX^2-\frac{(sumX)^2}{n} ]$

∑X= 20 + 18 + 23 + 30 + 20 + 12 + 24 + 9 + 25 + 15 + 8 + 11 + 15 + 34

∑X= 264

∑X²= 20² + 18² + 23² + 30² + 20² + 12² + 24² + 9² + 25² + 15² + 8² + 11² + 15² + 34²

∑X²= 5770

n= 14

S²= $\frac{1}{13}[5770-\frac{(264)^2}{14} ]$

S²= 60.90

Standard deviation

The standard deviation is the square root of the variance

S= √S²= √60.90= 7.80

Coefficient of variation

Is a relative standard deviation, it is defined as the division of the standard deviation (S) by the mean (X[bar)]. It has not units and is usually expressed in percentage. It shows the variability in relation to the mean.

C.V.= $\frac{S}{X[bar]}$ *100 = $\frac{7.80}{18.86}$ *100= 41.36%

The mean or average is a measurement of position and gives you an idea of the central value of the distribution of the data.

X[bar]= ∑X/n= 264/14= 18.86

Range

In the interval between the max and min values. It allows you to have an idea of the dispersion of the values.

R= Xmax - Xmin= 34 - 8= 26

Xmax= 34

Xmin= 8

Inter Quartile Range

Is the difference between Quantile 1 (C₁) and Quantile 3 (C₃). It shows the 50% mid values of the sample.

IQR= C₃ - C₁= 23.5 - 11.5 = 12

Quantile 1 (C₁) is the value that leaves 25% of the sample below and 75% of the sample above.

Pos1: n/4= 14/4= 3.5

The first quantile is the number between position 3 and position 4

8, 9, 11, 12, 15, 15, 18, 20, 20, 23, 24, 25, 30, 34

C₁= (11+12)/2= 11.5

Quantile 3 (C₃) is the value that leaves 75% of the sample below and 25% of the sample above.

Pos3: n*3/4= 14*3/4= 10.5

The third Quantile is between position 10 and 11

8, 9, 11, 12, 15, 15, 18, 20, 20, 23, 24, 25, 30, 34

C₃= (23+24)/2= 23.5

The measurements of variation don't allow you to know the origin of the data, that it is from consecutive years.

I hope it helps!

6 0

2 years ago