Lin Ying belongs to an athletic club. In 800 m races her times are normally distributed with mean 128 seconds and standard deviation
4 seconds.
(a) What is the probability of her time in an 800 being between 120 and 130 seconds?
(b) What time will she beat in 70% of her races?
Julie belongs to the same club. In 800 m races 85% of her times are less than 140 seconds and 70% are less than 135 seconds. Her times are normally distributed.
(c) Find the mean and standard deviation of Julie's times, each correct to two significant figures.
(d) What is the probability that in an 800 m race Lin Ying will beat Julie?
(e) The club has to choose one of these two athletes to enter a major competition. In order to qualify for the final rounds it is necessary to achieve a time of 114 seconds or less in the heats. Which athlete should be chosen and why?

Answer:

[2,6]

Step-by-step explanation:

3x+5y=36

5x-4=y

3x+5(5x-4)=36

3x+25x-20=36

28x-20=36

28x=56

x=2

5x-4=y

5*2-4=y

10-4=y

6=y

Answer:

n is equal to the square root of 204

n=[tex]\sqrt{204}[/tex]

n=2[tex]\sqrt{51}[/tex]

Answer:

-5

Step-by-step explanation:

The equation given is written in slope-intercept form (y = mx + b). In this form, 'm' represents the slope of a line and 'b' represents the y-intercept of the line. Since the equation asks for the slope, we can simply look at the value of 'm' in the equation. Then, we will find the slope.

slope - intercept form

y = mx + b

given equation

-y = -5x + 9

values

m = slope = -5

b = y-intercept = 9

See attachment for your problem set up.

Answer:

This is a 25% decrease

Step-by-step explanation:

Find the difference between the two prices

24- 18 = 6

Take that over the original price

6 /24 = 1/4

Change to decimal form

.25

Change to percent form

25%

This is a 25% decrease

Answer:

B

Step-by-step explanation:

3 3/4 +r _3 3/4= 5 3/8_3 3/4

Answer:

[tex]\$160[/tex]

Step-by-step explanation:

To find the cost of the entire fence, we need to first determine the lawn's length before calculating its perimeter.

Area of rectangular lawn = [tex]lw[/tex] (formula for the area of a rectangle)

[tex]364=14l[/tex]

[tex]l=26[/tex] feet

Now that we have the lawn's length and width, we can calculate the perimeter:

Perimeter [tex]= 2l+2w[/tex] (formula for the perimeter of a rectangle)

[tex]=2(26)+2(14)[/tex]

[tex]=80[/tex] feet

Since each foot of lawn costs $2, then the cost of the entire fence will be:

[tex]80\times2 = \$160[/tex]

∴ The entire fence costs [tex]\$160[/tex].

Hope this helps :)

Answer:

y=-5/2x+1

Step-by-step explanation:

-1-4 ( -5 )

0- (-2 ) = 0+2 ( 2 )

-5/2

y=-5/2x+b

4=-5/2( -2 ) +b

4= 5+b

Subtract 4 from 5 ( 1 )

b=1

y=-5/2x+1

Hope this helped, Have a Great Day!!

The equation of the line passing from the given points is y = -5x/2-1

An equation is a mathematical statement that shows that two mathematical expressions are equal.

Given that, a line is passing through two points (-2, 4) and (0 -1)

We know that, the equation of a line passing through two points is given by,

y-y₁ = (y₂-y₁/x₂-x₁)(x-x₁)

Therefore,

y-4 = (-1-4)/(0+2)(x+2)

y-4 = -5/2(x+2)

y = -5x/2-5+4

y = -5x/2-1

Hence, The equation of the line passing from the given points is y = -5x/2-1

For more references on equations, click;

https://brainly.com/question/29657992

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Answer:

x=2

Hope I helped

Answer:

X=2

Step-by-step explanation:

Please mark brainliest.

Answer:

200 pounds per crate

Step-by-step explanation:

because if you divide 1600 by 8 than you get 200 pounds. then that is you unit rate

Answer:

250

2000 divided by 8

Step-by-step explanation:

Answer:

All are corrects.

Step By Step Explanation:

It's all the same thing.

Answer:

69300 is the total amount without being rounded but after being rounded the answer is 5600

Step-by-step explanation:

You put it in the other comment section for free points

Answer:

Hence 262 adults and 88chidren are in the audience

Step-by-step explanation:

Let the number adults be x

Let the number of children be y

If there are 350seats in the theatre then;

x+y =350 .... 1

Also if $10.50was charged for adults and $7.50 for children with total amount of $3411, then;

10.50x + 7.50 y = 3411..... 2

Solve simultaneously

From 1, x = 350-y

Substitute into 2:

10.50(350-y) +7.50y = 3411

3675-10.5y+7.50y = 3412

3675-3y = 3411

-3y = 3411-3675

-3y = -264

y = 264/3

y = 88

From 3: x = 350-y

x = 350-88

x = 262

Hence 262 adults and 88chidren are in the audience

Answer:

x = 80 degrees

y = 25 degrees

Step-by-step explanation:

First find angle BCA.

We know a line is 180 degrees, and angle BCD is 130. So 180-130 = 50 degrees for angle BCA.

Since it is isosceles (two lines on both sides of triangle ABC) this means the bottom two angles are the same. Now we know the two angles to find missing angle X.

50+50+ x = 180 degrees

x= 180 - 100 = 80 degrees

Next we know triangle BCD is isosceles, so angle BDC and angle CBD are the same. We know the third angle is 130 degrees.

So 180 - 130 = 50 degrees split between two angles that are the same. So one angle is 50/2 = 25 degrees.

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Answer:

120 apples and 100 oranges

Step-by-step explanation:

6/11 x 220 = 120 apples

5/11 x 220 = 100 oranges

Solution :

According to the question, as given by the Video Game Voters.org website, 38 percent of all the games that is sold in the United States would be purchased by the women.

Now this is considered as a joint event. This is because the above statement consists of two events.

1. Video games are sold in the United States.

2. Women purchased video games.

The above two events are working or happening at the same time. And 0.38 is the likelihood of the games to be sold in the U.S. and the games that is sold in U.S. are being purchased by the women.

Answer:

i dlnt know 15 I think not sure

Answer: 0 i guess i dont know

Step-by-step explanation:

y=9

x=12

hope its right pls do mark me the brainleist

Answer:

a d f g

Step-by-step explanation:

Answer:

its abfg

Step-by-step explanation:

Answer:

1 pencil will be for 1.75 $

Answer:

$1.75 for each pencil.

Step-by-step explanation:

if you're asking the price for each pencil then its 1,75 for each because 8 multiplied by 1.75 is 14 :))

Answer:

52 , 165 , 173 is Pythagorean triple.

Step-by-step explanation:

Pythagorean triple;

a² + b² = c²

Computation:

88² + 105² ≠ 139²

39² + 80² ≠ 119²

38² + 198² ≠ 202²

52² + 165² = 173²

So,

52 , 165 , 173 is Pythagorean triple.

Answer:

1000 g

Step-by-step explanation:

That is the answer

Answer:

Step-by-step explanation:

1 gram.

Answer:

thats not a question

Step-by-step explanation:

Answer:

No

Step-by-step explanation:

Answer:

73

Step-by-step explanation:

since it's a right angle it equals 90° and you already know there 17°. so you just subtract 90-17

Answer:

answer is 3 upon 4

Step-by-step explanation:

because if we reduce 18/24 to its lowest term so first we have to reduce 18 to and then 24 --- 18 is factor of 9x2 and 24 is factor of 12x2 then we have to cut 2 in both and there is answer 9 upon 12 still it is reducing so 3x3 is 9 and 3x4 is 12 so now we have to cut 3 in both the answer is 3 upon 4

Answer:

I don't like mathematics

Answer:

AE and BD use the same lines for both triangles so the angles for C are the same. this means that all the angles are congruent between both triangles.

Step-by-step explanation:

Answer:

The distance across the river d=175ft

Step-by-step explanation:

As◇ ABC& ◇ EDC are similar, BC/CD=AB/ DE

4x/7x=100/d

d=100×7/4=175