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2 years ago

11

Mean of Frequency Tables

1 answer:

slavikrds [6]2 years ago

5 0

Answer: 1. 41.67years

2. £9.21

3. 7.75cm

Step-by-step explanation:

1. At a party, thirty people have an age of 30, forty have an age of 40 and fifty an age of fifty. What is their average age?

Total ages = (30 × 30) + (40 × 40) + (50 × 50) = 900 + 1600 + 2500 = 5000

Total number of people = 30 + 40 + 50 = 120

Average age = Total ages / Total number of people

= 5000/120

= 41.67 years

2. In a hardware shop, there are 30 spanners costing £6, 55 hacksaws costings £9 and 10 soldering irons costings £20. What is the average cost per item?

Total cost of items = (30 × £6) + (55 × £9) + (10 × £20) = £180 + £495 + £200 = £875

Total number of items = 30 + 55 + 10 = 95

Average cost per item = £875/95 = £9.21

3. Using this frequency table, find the average height of a turnip.

Height (to nearest cm)

6cm 7cm 8cm 9cm 10cm

Frequency: 3 8 12 4 1

Total height = (3 × 6cm) + (8 × 7cm) + (12 × 8cm) + (4 × 9cm) + (1 × 10cm) = 18cm + 57cm + 96cm + 36cm + 10cm = 217cm

Total number of turnips = 3 + 8 + 12 + 4 + 1 = 28

Average height = 217cm/28 = 7.75cm

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romanna [79]

Average rate of change = (x(4) - x(2))/(4 - 2) = ((4 + 2(4)^2) - (2 + 2(2)^2))/2 = ((4 + 2(16)) - (2 + 2(4)))/2 = ((4 + 32) - (2 + 8))/2 = (36 - 10)/2 = 26/2 = 13.

Therefore, average velocity is 13 m/s

7 0

2 years ago

Circle towns limit form a perfectly circular shape that has a population of 20000 in the population density of 480 people per sq

Alex

Answer:

$D =\frac{P}{\pi X^2}$

And solving for the radius we got:

$X = \sqrt{\frac{P}{\pi D}}$

And replacing the data given we got:

$X = \sqrt{\frac{480 \frac{people}{km^2}}{\pi *20000 people}}= 0.0874Km$

And this value converted to meters is $X = 87.40 m$

Step-by-step explanation:

For this case we know the population size $P = 20000$ and we also know the population density $D = 480 \frac{people}{km^2}$

We can assume that the area is a circle. We also know that the formula for the population density is given by:

$D= \frac{P}{A}$

Where P represent the number of people and A the area. Since we are assuming a circle then the area is given by:

$A = \pi X^2$

With X the radius of the circle

And then the populationd density become:

$D =\frac{P}{\pi X^2}$

And solving for the radius we got:

$X = \sqrt{\frac{P}{\pi D}}$

And replacing the data given we got:

$X = \sqrt{\frac{480 \frac{people}{km^2}}{\pi *20000 people}}= 0.0874Km$

And this value converted to meters is $X = 87.40 m$

6 0

3 years ago

1. PART A: Determine the missing lengths:

Otrada [13]

#1

Divide into two rectangles

$\\ \tt\hookrightarrow "1"=14-12=2$

$\\ \tt\hookrightarrow "2"=3+1=4$

#2

$\\ \tt\hookrightarrow P=14+1+12+3+2+4=36$

#3

$\\ \tt\hookrightarrow A=14(1)+3(2)=14+6=20units^2$

3 0

1 year ago

Read 2 more answers

Javier asks his mother how old a tree in their yard is. His mother says, "The sum of 10 and two-thirds of that tree's age, in ye

Sloan [31]

Answer:

His error is adding 10 and 2/3 before multiplying by a(age of the tree)

Step-by-step explanation:

The sum of 10 and two-thirds of that tree's age, in years, is equal to 50.

Correct equation

Sum = addition (+)

two-thirds = 2/3

The tree's age = a

10 + 2/3a = 50

2/3a = 50 - 10

2/3a = 40

a = 40 ÷ 2/3

= 40 × 3/2

= 60

a = 60 years

Javier writes the equation

(10 + two-thirds) a = 50

(10 + 2/3)a = 50

(30+2/3)a = 50

32/3a = 50

a = 50 ÷ 32/3

= 50 × 3/32

= 150/32

a = 150/32

His error is adding 10 and 2/3 before multiplying by a(age of the tree)

5 0

2 years ago

Mr nealy has $107.40 he withdrew $120 from the ATM. Does he have enough money to pay for the meal? If he has enough money, how m

guapka [62]

Answer: He has enough

Step-by-step explanation:120-107.40=12.60

7 0

2 years ago