Running times for 400 meters are Normally distributed for young men between 18 and 30 years of age with a mean of 93 seconds and a standard deviation of 16 seconds. How fast does a man have to run to be in the top 1% of runners?

Answer:

B.

✔ -4

Step-by-step explanation:

E 2021

Answer:

Step-by-step explanation:

We can write some equations to describe the given relationships:

  A = B - 2 . . . . . A is 2 kg lighter than B

  A = C/5 . . . . . . A is 1/5 the weight of C

  A+C = 3B . . . . together, A and C are 3 times the weight of B

__

Let's solve for A.

  B = A+2 . . . from the first equation

  C = 5A . . . . from the second equation

  A +5A = 3(A+2) . . . . substituting for B and C in the third equation

  6A = 3A +6

  3A = 6

  A = 2

__

  B = A+2 = 4

  C = 5A = 10

Watermelon A weighs 2 kg; B weighs 4 kg; and C weighs 10 kg.

Answer:

2 kg 4 kg 10 kg

I BLESS THE EYES!

Answer:

(See explanation below for further detail/Véase la explicación abajo para mayores detalles)

Step-by-step explanation:

(This exercise is written in Spanish and explanations will be held in such language)

a) Las temperaturas quedan representadas a continuación:

Quito - Temporada Fría

Intervalo

[tex]5 ^{\circ}C \leq t \leq 18^{\circ}C[/tex] (Este intervalo indica si el dato puede pertenecer a la temporada fría)

Conjunto

[tex]C = \{\forall t \in \mathbb {R}| 5 \leq t \leq 18\}[/tex] (Este conjunto acumula todo el registro de las temperaturas de la temporada fría)

Quito - Temporada Cálida

Intervalo

[tex]4 ^{\circ}C \leq t \leq 30^{\circ}C[/tex] (Este intervalo indica si el dato puede pertenecer a la temporada cálida)

Conjunto

[tex]H = \{\forall t \in \mathbb {R}| 4 \leq t \leq 30\}[/tex] (Este conjunto acumula todo el registro de las temperaturas de la temporada cálida)

b) La temperatura de la ciudad de Quito pertenece esencialmente a dos intervalos:

Intervalo de Temporada Fría:

[tex]5 ^{\circ}C \leq t \leq 18^{\circ}C[/tex]

Intervalo de Temporada Cálida:

[tex]4 ^{\circ}C \leq t \leq 30^{\circ}C[/tex]

c) Toda temperatura mayor o igual que 4 °C y menor o igual que 30 °C.

d) Temperaturas mayores o iguales a 5 °C y menores o iguales a 18 °C.

e) Temperaturas mayores o iguales a 4 °C y menores o iguales a 30 °C.

Answer:

P = 0.5207

Step-by-step explanation:

First, we have three options: Just the first card is a diamond or an ace, Just the second card is a diamond or an ace and both cards are diamonds or aces.

Additionally, there are 16 cards that are diamond or aces in a standard deck of 52 cards (13 diamonds and 3 aces that are not diamonds). It means that there are 36 cards that are not diamond or aces (52 - 16 = 36).

So, the probability that just the first card is a diamond or an ace is calculated as:

[tex]P_1=\frac{16}{52}*\frac{36}{52}=0.2130[/tex]

At the same way, the probability that just the second card is a diamond or an ace is:

[tex]P_2=\frac{36}{52}*\frac{16}{52}=0.2130[/tex]

Finally, the probability that both cards are diamonds or aces is:

[tex]P_3=\frac{16}{52}*\frac{16}{52}=0.0947[/tex]

Therefore, the probability that at least one of the cards is a diamond or an ace is:

[tex]P=P_1+P_2+P_3\\P=0.2130+0.2130+0.0947\\P=0.5207[/tex]

Answer:

A word problem for that would be Sam had 28 chocolates and Bob took away 15. How many does Sam have left?

Step-by-step explanation:

I don't know how to show work for writing a word problem. Sorry

Answer:

Step-by-step explanation:

Jane has $15 in her bank account. She wrote a $28 check for buying a fiction book. How much is her balance now?

Answer:

123.7 meters

Step-by-step explanation:

If you draw a diagram, this will be a rectangle and the line across cuts it into a right triangle, with a base of 120 and a height of 30. The need to know the length of the hypotenuse of the triangle, so we can use the pythagorean theorem.

30^2 + 120^2 = c^2

c=123.7

Answer:

33084

Step-by-step explanation:

22056 divided by 2 =11028

altogether (on sunday and monday) the total amount would be..

22056+11028=33084

Answer:

33084

Step-by-step explanation:

If 22056 people came to the game on Sunday and Half as many people came on Monday, you do

22056 divided by 2. this is how many people cam on monday

Add this answer to 22056 and this is how many people came on both days.

Answer:

There are 55 sweets in total.

Step-by-step explanation:

The total number of sweets is t.

Henry, Brian and Colin share some sweets in the ratio 6:4:1.

This means that Henry earns [tex]\frac{6}{6+4+1} = \frac{6}{11}[/tex] of the total(t).

Brian earns [tex]\frac{4}{11}[/tex] of the total.

Colin earns [tex]\frac{1}{11}[/tex] of the total

Henry gets 25 more sweets than Colin.

Henry earns [tex]\frac{6t}{11}[/tex]

Colin earns [tex]\frac{t}{11}[/tex]

So

[tex]\frac{6t}{11} = \frac{t}{11} + 25[/tex]

Multiplying everything by 1

[tex]6t = t + 275[/tex]

[tex]5t = 275[/tex]

[tex]t = \frac{275}{5}[/tex]

[tex]t = 55[/tex]

There are 55 sweets in total.

Answer: 1. (4, 8); 2. (3, 4)

Step-by-step explanation: I tried to get this to you fast but I can give you an explaination if you would like one :)

Answer:

326

Step-by-step explanation:

l x w

7x8

25x6

4x30

326

Answer:

a.

Number:      0,    1,       2,     3,      4,       5,    6,    7,     8

Frequency:  6,    12,     13,     15,     5,      3,     3,    1,    1

b. The proportion of the batches that have at most is 0.864

Step-by-step explanation:

a. The given data are;

2 1 2 3 1 1 3 2 0 5 3 3 1 3 2 4 7 0 2 3

0 4 2 1 3 1 1 3 4 1 2 3 2 2 8 4 5 1 3 1

5 0 2 3 2 1 0 6 4 2 1 6 0 3 3 3 6 2 3

The frequencies are;

x     fx  

0     6

1      12

2     13

3      15

4      5

5      3

6      3

7       1

8       1

The relative frequency are;

x     Rfx  

0   0.102

1   0.203

2   0.220

3   0.254

4   0.085

5   0.051

6   0.051

7   0.017

8   0.017

b. The proportion of the batches that have at most 4 is given as follows;

The number of the batches that have at most 4 = 6 + 12 + 13 + 15 + 5 = 51

Therefore, the proportion of the batches that have at most 4 = 51 / 59 = 0.864.

Answer:

0

Step-by-step explanation:

Tuesday : -1/2

Wednesday + 3/4

Thursday : -3/8

Add them together

-1/2 + 3/4- 3/8

Get a common denominator

-4/8 + 6/8 - 3/8

-1/8

The closest integer value to -1/8 is 0

PROOF:

[tex]y^4-(y^2-9)(y^2+9)\\=y^4 -(y^4-81)\\=y^4-y^4+81\\=81[/tex]

And 81 is ALWAYS divisible by 9

Answer:

Its 9*9

Step-by-step explanation:

The equation equals 81 and 9*9=81.

Have a great day! :)

Answer:

A-using the associative property

Step-by-step explanation:

Answer: 400

Step-by-step explanation:

25% is equal to one quarter (1/4). If theres 100 red gumballs then there must be 300 more gumballs in the machine because a quarter of a number is always even.

Answer:

mean:12

Step-by-step explanation:

The population mean or sample mean as indicated in the given samples is 14

A mean in math is the average of a data set, found by adding all numbers together and then dividing the sum of the numbers by the number of numbers.

Mathematically,

Mean = Sum of the observations/number of observations

Now the given sample is,

17, 11, 8, 12, 22

So, Number of sample = 5

Thus, Mean = Sum of the sample /number of sample

Mean = (17 + 11 + 8 + 12 + 22) / 5

⇒ Mean = 70/5

⇒ Mean = 14

Thus, the population mean or sample mean as indicated in the given samples is 14

To learn more about mean :

https://brainly.com/question/21479395

#SPJ2

Answer:

24 beads

Step-by-step explanation:

beads in 4 sheet=32

beads in 1 sheet=32/4=8

beads in 3 sheet=8*3=24

Answer:

Assuming that you can make the same number of beads with 1 sheet of paper, Tameka can make 24 beads with 3 sheets of paper.

Answer:

160 off 20p coins

Step-by-step explanation:

20 p coins= 640 - 640*(3/8+3/8)= 640*(1- 6/8)= 640 * 2/8= 640* 1/4= 160

Answer:

a) [tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]    

The degrees of freedom are given by:

[tex]df=n-1=45-1=44[/tex]  

The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4

b) [tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]  

Step-by-step explanation:

Information given

[tex]\bar X=18.4[/tex] represent the sample mean

[tex]s=2.2[/tex] represent the sample standard deviation

[tex]n=45[/tex] sample size  

[tex]\mu_o =17.5[/tex] represent the value to verify

[tex]\alpha=0.05[/tex] represent the significance level

t would represent the statistic

[tex]p_v[/tex] represent the p value

Part a

We want to test if the true mean is higher than 17.5, the system of hypothesis would be:  

Null hypothesis:[tex]\mu \leq 17.5[/tex]  

Alternative hypothesis:[tex]\mu > 17.5[/tex]  

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex]  (1)  

And replacing we got:

[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]    

The degrees of freedom are given by:

[tex]df=n-1=45-1=44[/tex]  

The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4

Part b

The p value would be given by:

[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]  

Answer:

We use the binomial distribution to describe this situation.

The mean number of phone sales is 749.7 with a standard deviation of 15.

Step-by-step explanation:

For each shopper, there are only two possible outcomes. Either they plan to purchase the newly released smart phone, or they do not. Each customer is independent of other customers. So we use the binomial distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

The standard deviation of the binomial distribution is:

[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]

Fifty random shoppers at an electronics store have been interviewed and 35 of them intend to purchase a newly released smart phone.

This means that [tex]p = \frac{35}{50} = 0.7[/tex]

What are its mean and standard deviation of phone sales if we are concerned about 1071 shoppers that day

1071 shoppers, so [tex]n = 1071[/tex]

Mean

[tex]E(X) = 1071*0.7 = 749.7[/tex]

Standard deviation

[tex]\sqrt{V(X)} = \sqrt{1071*0.7*0.3} = 15[/tex]

The mean number of phone sales is 749.7 with a standard deviation of 15.

Answer:

44°

Step-by-step explanation:

A pair of angles formed from the intersection of two lines opposite to each other at the point of intersection (vertex) is called vertically opposite angles. These vertically opposite angles are congruent to each other (that means they are equal).

Since opposite angles are equal, the equation needed to calculate w is given as:

80° = 36° + w

w = 80° - 36°

w = 44°

Answer:

Step-by-step explanation:

image attached (representing first perpetuity on number line)

Present value is 7.21

[tex]7.21=\frac{1}{1-u^2} \\\\1-\frac{1}{7.21} =u^2\\\\\frac{6.21}{7.21} =(1+i)^{-2}\\\\(1+i)^2=\frac{7.21}{6.21} \\\\(i+1)=\sqrt{\frac{7.21}{6.21} }\\\\ i=\sqrt{\frac{7.21}{6.21} } -1\\\\=0.77511297[/tex]

image attached (representing second perpetuity on number line)

we have ,

[tex]7.21=\frac{Ru}{1-u^3}[/tex]

Here,

[tex]V=\frac{1}{1+i}[/tex]i

i = 0.077511297 + 0.01

[tex]\therefore V =\frac{1}{1.087511295} =(1.087511297)^-^1\\\\7.21=\frac{R(1.087511297)^-^1}{1-(1.087511297)^-^3} \\\\7.21=4.132664645R\\\\R=\frac{7.21}{4.132664645} \\\\R= 1.7446370\approx1.74[/tex]

Therefore, value of R is 1.74

Answer:

y = (x+6) (x+1) or in quadratic form: y = x² + 7x + 6

Step-by-step explanation:

Answer:

D.

Step-by-step explanation:

Since opposite angles of a quadrilateral inscribes in a circle add up to 180°

So,

<P + <N = 180°

2x+2x-12 = 180°

4x = 180+12

4x = 192

Dividing both sides by 4

x = 48

Now

<P = 2(48)

<P = 96

Now

<N = 2(48)-12

<N = 96-12

<N = 84

Answer:

so we have an inequality for y -

7.995<y<8.005

Then now we need in inequality for x

(y-4)/5 = x

so that means that so if we have (7.995-4)/5 we get 3.995/5 = 7.99

so we have our first 7.99<x<b

Now we solve for b

So that means that 5.005/5 = 1.001

since we are changing it we switch our signs

from 7.99<x<1.001

we do 7.99>x>1.001

therefore

1.001<x<7.99

Answer:

0.795 [tex]\leq[/tex] y [tex]\leq[/tex] 0.805

Step-by-step explanation:

8 = 5x + 4

5x = 4

x = 4/5 or 0.800

therefore 0.800 + .005 and 0.800 - .005 =

0.795 [tex]\leq[/tex] y [tex]\leq[/tex] 0.805

Answer:

A: 97π/18 m

Step-by-step explanation:

Central Angle = 97°

In radians:

97° = 97π/180

Now

S = r∅

S = (10)(97π/180)

S = 97π/18 m

Answer:

The answer is option 1.

Step-by-step explanation:

Given that the formula for length of Arc is Arc = θ/360×2×π×r when r represents the radius of circle. Then, you have to substitute the following values into the formula :

[tex]arc = \frac{θ}{360} \times 2 \times \pi \times r[/tex]

Let θ = ∠VCW = 97°,

Let r = 10m,

[tex]arc = \frac{97}{360} \times 2 \times \pi \times 10[/tex]

[tex]arc = \frac{97}{360} \times 20 \times \pi[/tex]

[tex]arc = \frac{97}{18} \pi \: m[/tex]

Answer:

The answer of top prism is 262

and down prism is 478

The upper figure is triangular prism.

so, we use bh+2ls+lb formula

B=5

h=3

s=4

l=19

Now,

surface area of triangular prism = bh+2ls+lb

= 5×3+2×19×4+19×5

= 262

The down figure is rectangular prism.

so, we use 2lw+2lh+2hw

l=5

h=6

w=19

Now,

The area of rectangular prism = 2lw+2lh+2hw

= 2×5×19+2×19×6+2×5×6

= 478

Answer:

[tex]P(210<X<290)=P(\frac{210-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{290-\mu}{\sigma})=P(\frac{210-202}{70}<Z<\frac{290-202}{70})=P(0.114<z<1.26)[/tex]

And we can find this probability with this difference

[tex]P(0.114<z<1.26)=P(z<1.26)-P(z<0.114)[/tex]

And we can find the difference with the normal standard distirbution or excel:

[tex]P(0.114<z<1.26)=P(z<1.26)-P(z<0.114)=0.896-0.545=0.351[/tex]

Step-by-step explanation:

Let X the random variable that represent the hotel room cost of a population, and for this case we know the distribution for X is given by:

[tex]X \sim N(202,70)[/tex]  

Where [tex]\mu=202[/tex] and [tex]\sigma=70[/tex]

We are interested on this probability

[tex]P(210<X<290)[/tex]

The z score formula is given by:

[tex]z=\frac{x-\mu}{\sigma}[/tex]

Using the formula we got:

[tex]P(210<X<290)=P(\frac{210-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{290-\mu}{\sigma})=P(\frac{210-202}{70}<Z<\frac{290-202}{70})=P(0.114<z<1.26)[/tex]

And we can find this probability with this difference

[tex]P(0.114<z<1.26)=P(z<1.26)-P(z<0.114)[/tex]

And we can find the difference with the normal standard distirbution or excel:

[tex]P(0.114<z<1.26)=P(z<1.26)-P(z<0.114)=0.896-0.545=0.351[/tex]

Answer:

[tex]t \approx 17.690\,min[/tex]

Step-by-step explanation:

This differential equation is a first order linear differential equation with separable variables, whose solution is found as follows:

[tex]\frac{dy}{dt} = - \frac{1}{53} \cdot (y - 17)[/tex]

[tex]\frac{dy}{y-17} = -\frac{1}{53} \, dt[/tex]

[tex]\int\limits^{y}_{y_{o}} {\frac{dy}{y-17} } = -\frac{1}{53} \int\limits^{t}_{0}\, dx[/tex]

[tex]\ln \left |\frac{y-17}{y_{o}-17} \right | = -\frac{1}{53} \cdot t[/tex]

[tex]\frac{y-17}{y_{o}-17} = e^{-\frac{1}{53}\cdot t }[/tex]

[tex]y = 17 + (y_{o} - 17) \cdot e^{-\frac{1}{53}\cdot t }[/tex]

The solution of the differential equation is:

[tex]y = 17 + 74\cdot e^{-\frac{1}{53}\cdot t }[/tex]

Where:

[tex]y[/tex] - Temperature, measured in °C.

[tex]t[/tex] - Time, measured in minutes.

The time when the cup of coffee has the temperature of 70 °C is:

[tex]70 = 17 + 74 \cdot e^{-\frac{1}{53}\cdot t }[/tex]

[tex]53 = 74 \cdot e^{-\frac{1}{53}\cdot t }[/tex]

[tex]\frac{53}{74} = e^{-\frac{1}{53}\cdot t }[/tex]

[tex]\ln \frac{53}{74} = -\frac{1}{53}\cdot t[/tex]

[tex]t = - 53\cdot \ln \frac{53}{74}[/tex]

[tex]t \approx 17.690\,min[/tex]

Answer:

[tex]y=300(1+0.16)^x[/tex]

Step-by-step explanation:

 [tex]A= P(1+r )^t[/tex]

Where

A =final amount  = y

P=initial principal balance = $300

r=interest rate  = 16%= 0.16

t=number of time periods elapsed= x

Hence the equation to model his account balance/ final amount A (y) after time (x) years is

[tex]y=300(1+0.16)^x[/tex]