2) There are 40 boys and 16 girls in a class of students. What is the ratio of girls to students?

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Answer:

Step-by-step explanation:

One way to write the relationship between time, speed, and distance is ...

  time = distance/speed

For the first part of the trip, the time is ...

  t1 = 240/r

For the second part of the trip, the time is ...

  t2 = 72/(r+10)

The total time is 6 hours, so we have ...

  t1 +t2 = 6

  240/r +72/(r+10) = 6

We can simplify this a bit by multiplying by (r)(r+10)/6 to get ...

   40(r+10) +12(r) = r(r+10)

  r² -42r -400 = 0 . . . . . . . . subtract the left side and collect terms

  (r -50)(r +8) = 0 . . . . . . . . factor

  r = 50 . . . . . the positive solution of interest.

The two average speeds were 50 mph and 60 mph.

Answer:

At 4:00 PM the distance between the two ships is 104.40 kilometers.

Step-by-step explanation:

Given that at noon, ship A is 150 km west of ship B, and ship A is sailing east at 30 km / h and ship B is sailing north at 25 km / h, to determine how fast is the distance between the ships changing at 4:00 PM the following calculation must be performed:

150 - (30 x 4) = 150 - 120 = 30

0 + (25 x 4) = 0 + 100 = 100

30 ^ 2 + 100 ^ 2 = X ^ 2

√ (900 + 10,000) = X

√10,900 = X

104.40 = X

Therefore, at 4:00 PM the distance between the two ships is 104.40 kilometers.

Answer:

0.5759

Step-by-step explanation:

Answer:

in 3 minutes ;

44 × 3 = 132 copies

and 45 soconds;

[tex]45 \: seonds \: = \frac{3}{4} \: mınutes[/tex]

44 × ¾ = 33 copies

HAVE A NİCE DAY

Step-by-step explanation:

GREETİNGS FROM TURKEY ツ

Answer:

the answer is -6. you just subtract 2 with 8

Answer:

a)17.92

b) 16.83 .... 21.17

Step-by-step explanation:

ρ→   z

0.14 = -1.080319341

-1.080 = (x - 19)/1 = 17.92

~~~~~~~~~~~~~~~~~~

3% / 2 = 1.5%

1.5% - 98.5%

ρ→   z

0.015 = -2.170090378 ....  -2.17 = (x-19) =16.83

0.985 = 2.170090378  ....   2.17 = (x-19) =21.17

Answer:

x > -2

Step-by-step explanation:

the graph stops at x = -2 and doesn't move further down

Answer:

1 : 0.088

2 : 0.12

3 : 0.07

Step-by-step explanation:

45 Rebullicans

50 Democrats

5 independents

Total = 100

Selection =  3

Part 1:

(45 C 3) / (100 C 3) = 0.088

Part 2:

(50 C 3) / (100 C 3) = 0.12

Part 3:

(45 C 1) x (50 C 1) x (5 C 1) / (100  C 3) = 0.07

Is this the whole question?

Step-by-step explanation:

Are you done typing or there's more to it.

Answer:

You look at your graph and or chart and start to make note

Your looking for the following tyoe data

1-5, 5-10  etc such distribution is usually done on y axes for histograms and x axes for all other graphs.

If there is a group data or frequency then you need to multiply the highest group data ie) from 0-5 it is 2.5

Then 2.5 times the actual frequency which is in the chart = say it says 4

Then 2.5 x 4 = 10

Then do the same for 5-10 = 7.5 midpoint

7.5 x frequency  of 2 = 15 and so on

Then 10-15 = 12.5 midpoint you show this by 10+15/2 = 12.5  frequency of 12.5 could be 6 as in example so 6 x 12.5 = 72  etc...

When you get all totals 10+ 15+ 72 in the fx bar you cna plot on graph and then see how many have a grade lower than 80

For histograms we dont do midpoint we do highest value then times it by frequency and so our grades for 0-5 = 5

and frequency is the number of students that got such mark so we do 5 x 4 = 20 and so on then divide this number by 5 again showing that 5 students got 5 or under

and keep adding these up, the reason we would need the fx totals ie) 20 for 0-5 is that you cna map it in a histogram by adding the number below it say its 0-5 = 5 and 5 x 4 = 20

but instead of doing separately thereafter 0-5 we just add the frequency amount to 20 so if its 5-10 = 10  then we get 10 x 2 = 20 and from 20 + 20 = 40

If no frequency was given we do 5 + 10 + 15 etc. until we get to our frequency that way.

Then after adding them all up we can use this amount to get our mean etc.

and to find how many are less than 80 if histograms boxes are shown we have to distribute from how many we know as total being first one 0-5 = 5 and count 5 into the box to see the frequency there.

Say the box is 25 little boxes we know then that 25/5 = 5 so the rate of frequency is 5 for each and that each box has the same frequency or the same distribution depending if frequency is shown a different way or not.

IF its box plot then the middle line is the median and you know its exactly half of frequency and can therafter work out quartiles and count down from 80 either using the given 79 number to the set start number at start of the whiskers.

Step-by-step explanation:

Answer:

0.9484 = 94.84% probability that the sample proportion of girls will be greater than 41%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Suppose 44% of the children in a school are girls.

This means that [tex]p = 0.44[/tex]

Sample of 727 children

This means that [tex]n = 727[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.44[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.44*0.56}{727}} = 0.0184[/tex]

What is the probability that the sample proportion of girls will be greater than 41%?

This is 1 subtracted by the p-value of Z when X = 0.41. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.41 - 0.44}{0.0184}[/tex]

[tex]Z = -1.63[/tex]

[tex]Z = -1.63[/tex] has a p-value of 0.0516

1 - 0.0516 = 0.9884

0.9484 = 94.84% probability that the sample proportion of girls will be greater than 41%

Answer:

y=¼x-6

Step-by-step explanation:

y=mx+c

y=¼x+-6

y=¼x-6

Answer:

Step-by-step explanation:

B looks like it would work.

You add speeds * time when you are travelling in opposite directions.

I don't know why you would add or subtract 1 as in A and C

120 * t = 540

t = 540/120

t = 4.5 hours.

So after 4.5 hours they are 540 miles apart.

Answer:

b

Step-by-step explanation:

Answer:

3/14

Step-by-step explanation:

it takes 3 days to construct a porch and 14 days to construct a family room

so porch/family room = 3/14

Brainliest if this was correct

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Answer:

  A. 3/2

Step-by-step explanation:

Point C is 3 units higher and 2 units right of point A. The slope is ...

  slope = rise/run = 3/2

Answer:

2. A counterclockwise rotation of 270 degrees about the origin.

Step-by-step explanation:

Point A before the transformation:

Before the transformation, point A was at (-2,2).

After the transformation, point A' is (2,2).

Point B:

Before the transformation, point B was at (-6,-3)

After the transformation, point B' is (-3,6).

Transformation rule:

From the transformations of points A and B, we get that the transformation rule is (x,y) -> (y,-x), which is a counterclockwise rotation of 270 degrees about the origin., and the correct answer is given by option 2.

Answer: 13/7 or as a decimal 1.857142857

How did i get the answer:

Step 1: Simplify both sides of the equation.

so 1/2 of 10 is 5, 1/2 of 16 is 8

-3/5 of 15 is -9 and -3/5 of -35 is POSITIVE 21

all together should look like 5x+8+−13=−9x+21

(now we have to combine like terms)

8+ -13= -5

5x -5 = -9x+21

Step 2: Add 9x to both sides

5x + 9x= 14x

14x -5 = 21

Step 3: Add 5 to both sides.

21+5= 26

14x=26

Step 4: Divide both sides by 14.

26/14= 1.85714286 or 13/7

Step-by-step explanation:

Double t

t+t=2t

Subtract v

2t-v

Subtract u

2t-v-u

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Answer:

  66 m

Step-by-step explanation:

The perimeter is the sum of the measures of all of the sides. There are two side measures that are missing from the diagram.

The missing horizontal measure is ...

  17 m - 8 m = 9 m

The missing vertical measure is ...

  16m -7 m = 9 m.

If you add these to the sum you already calculated, you will get the correct answer:

  48 m + 9 m + 9 m = 66 m . . . perimeter of the figure

_____

If you're paying attention, you see that the sum of the measures of the two shorter horizontal segments is the same as the measure of the longer horizontal segment. Likewise, the sum of the measurements of the two shorter vertical segments is the same as that of the longer vertical segment.

In other words, the perimeter of this (and any) L-shaped figure is the same as the perimeter of a rectangle having the same horizontal and vertical dimensions as the long sides of the figure.

  P = 2(17 m +16 m) = 2(33 m) = 66 m

Answer:

Step-by-step explanation:

If J can paint a room in 3 hours, in 1 hour she gets [tex]\frac{1}{3}[/tex] of the job done.

If A can paint a room in 4 hours, in 1 hour she gets [tex]\frac{1}{4}[/tex] of the job done. We need to find out how long it takes them if they paint together. The equation for this is:

[tex]\frac{1}{3}+\frac{1}{4}=\frac{1}{x}[/tex] where x is the number of hours it takes them to get the job done together. Multiply everything through by 12x to get

4x + 3x = 12 so

7x = 12 and

x = 1.7 hours to get the room painted together.

Answer:

Length = 14 m, Width = 7 m

Step-by-step explanation:

Let the length is l and width is b.

Width, b = l-7

Area of the rectangle, A = 98 m²

We know that, the area of a rectangle is as follow :

[tex]A=lb[/tex]

So,

[tex]98=l(l-7)\\\\98=l^2-7l\\\\l^2-7l-98=0\\\\l^2+7l-14l-98=0\\\\l(l+7)-14(l+7)=0\\\\l=14,-7[/tex]

Length can't be negative. So,

Width, b = 14-7 = 7 m

So, the dimensions of the rectangle are 14 m and 7 m respectively.

Given: ????=????−2????+5????

and ????=2????+????+3????

To find: We need to find the value of ????×????

Solution: Here given,

????=????−2????+5????

and ????=2????+????+3????

Therefore, solving these two we have, ????=0

So,????×????=0

Answer:

YES, they are equal

Step-by-step explanation:

Given the expressions

h(x) = 2x – 3;j(x) = - 4x + 6; k(x) = – 2x + 3

h(x) + j(x) = 2x – 3 + (-4x + 6)

h(x) + j(x) =  2x - 3 -4x + 6

h(x) + j(x) = 2x - 4x -3 + 6

h(x) + j(x) = -2x + 3 = k(x)

This shows that h(x) + j(x) =  k(x)

Answer:

78.2m

Step-by-step explanation:

Lenght of the arc= ( circumference) × ( fraction of the circle)

Circumference=2πr = 2×20×π

Radius=20 m

fraction of the circle can be calculated as 224°/360°= 0.662

Then substitute the values we have

Lenght of the arc=

(2×20×π) ×0.662

= 78.2,

Lenght of the arc is 78.2m

Answer:

Step-by-step explanation:

M

Answer:

0.0838 = 8.38% probability of obtaining a sample proportion less than 0.5.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Proportion of 0.6

This means that [tex]p = 0.6[/tex]

Sample of 46

This means that [tex]n = 46[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.6[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.6*0.4}{46}} = 0.0722[/tex]

Probability of obtaining a sample proportion less than 0.5.

p-value of Z when X = 0.5. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.5 - 0.6}{0.0722}[/tex]

[tex]Z = -1.38[/tex]

[tex]Z = -1.38[/tex] has a p-value of 0.0838

0.0838 = 8.38% probability of obtaining a sample proportion less than 0.5.

Answer:

Step-by-step explanation:

46.327=46 ( neaarest whole number)

-4.801=-5 (nearest whole number)

46-(-5)=46+5=51

Answer: Hi some data is missing attached below is the missing data

answer:

WMA = 174.53

Step-by-step explanation:

Determine the three-week weighted moving average with weights

( 1/2, 1/3, 1/6 )

Weighted moving average ( WMA ) = 174.53

MSE = ∑ (xi - WMA)^2 / n

        = 9.71

attached below is the detailed solution/table