a river generates a spring flood about 40% of the time. Based on these records, what is the chance that it will flood for at least three years in a row sometime during the next five years

Answer:

VERTEX: (0.75,25)    

Step-by-step explanation:

the vertex will be at [-b/2a, f(-b/2a)]

−16x2 + 24x + 16

4(-4x^2 + 6x +4)

a = -4, b=6,c=4

-6/-8 = 3/4

f(3/4) = 25

Let x and y be the amounts (in mL) of the 4% and 15% solutions, respectively, that the scientist needs to use.

He wants to end up with a 44 mL solution, so

x + y = 44 mL

Each milliliter of 4% solution contains 0.04 mL of acid, while each mL of 15% contains 0.15 mL of acid. The resulting solution should have a concentration of 12%, so that each mL of it contains 0.12 mL of acid. Then the solution will contain

0.04x + 0.15y = 0.12 × (44 mL) = 5.28 mL

of acid.

Solve for x and y. In the first equation, we have y = 44 mL - x, and substituting into the second equation gives

0.04x + 0.15 (44 mL - x) = 5.28 mL

0.04x + 6.6 mL - 0.15x = 5.28 mL

1.32 mL = 0.19x

x ≈ 6.95 mL

==>   y ≈ 37.05 mL

Answer:

10.5

Step-by-step explanation:

In the picture if you think about it, it has to be a number less than 15 since CB is 15. I picked 12.3 and got it wrong therefore it has to be 10.5.

Answer:

A) 10.5

Step-by-step explanation:

Answer:

D) 13

[tex]\sqrt{169} = 13[/tex]

Step-by-step explanation:

Answer:

The 98% confidence interval for the mean number of energy drinks consumed per week by teenagers is (5.8, 6).

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.98}{2} = 0.01[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.01 = 0.99[/tex], so Z = 2.327.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 2.327\frac{1.1}{\sqrt{1027}} = 0.1[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 5.9 - 0.1 = 5.8 drinks per week.

The upper end of the interval is the sample mean added to M. So it is 5.9 + 0.1 = 6 drinks per week.

The 98% confidence interval for the mean number of energy drinks consumed per week by teenagers is (5.8, 6).

Answer:  Choice A.   [tex]-x^2+2x+8[/tex]

Work Shown:

[tex](f - g)(x) = f(x) - g(x)\\\\(f - g)(x) = (2x+1) - (x^2-7)\\\\(f - g)(x) = 2x+1 - x^2+7\\\\(f - g)(x) = -x^2+2x+(1+7)\\\\(f - g)(x) = -x^2+2x+8\\\\[/tex]

which shows the answer is choice A.

Side note: be sure to distribute the negative to every term inside the second set of parenthesis. So you wouldn't say -(x^2-7) = -x^2-7. If you did this error, then you'd get to the wrong answer choice C.

Answer:

hope it helps u plz mark me brainliest mate

Step-by-step explanation:

(f-g)(x)=2x+1-(x^2-7)

(f-g)(x)=2x+1-x^2+7

(f-g)(x)= -x^2+2x+8

this is the correct answer

Answer:

Speed of canoiest is 10 miles/hour.

Speed of current is 2 miles/hour.

Step-by-step explanation:

Let the speed of canoiest is v and the speed of current is u.

distance = speed x time

24 = (v + u ) x 2

v + u = 12 ..... (1)

Now

24 = (v- u) x 3

v - u = 8 .... (2)

By solving (1) and (2)

2 v = 20

v = 10 miles/hour

u = 2 miles/hour

Answer: 12

Step-by-step explanation:

Answer:

12

Step-by-step explanation:

Check the picture below

In the largest triangle, the missing side has length

√((11 + 5)² - x ²) = √(256 - x ²)

But it's also the hypotenuse of the triangle with side lengths 11 and y, so that its length can also be written as

√(11² + y ²) = √(121 + y ²)

so that

√(256 - x ²) = √(121 + y ²)

or, by taking the squares of both sides,

256 - x ² = 121 + y ²

y ² = 135 - x ²

In the smallest triangle, you have

5² + y ² = x ²   ==>   x ² = 25 + y ²

Substitute this into the previous equation and solve for y :

y ² = 135 - (25 + y ²)

y ² = 110 - y ²

2y ² = 110

y ² = 55

y = √55

Answer:

2.1n-2.1

Step-by-step explanation:

The increase is

1.10 (n-1)= 1.1n -1.1

Add this to the original amount

(n-1) + 1.1n - 1.1

2.1n-2.1

Answer:

There are two intersections.

(-3,1) and (-1,-3)

Step-by-step explanation:

Answer:

They intersect at (-3,1), and also (-1,-3)

Step-by-step explanation:

Graph:

Answer:

Hence the 90% confidence interval estimate of the population mean is [tex](79.24 , 97.44)[/tex]

Step-by-step explanation:

Given that,  

Point estimate = sample mean = [tex]\bar x[/tex] = 88.34  

sample standard deviation = s = 19.22  

sample size = n = 14  

Degrees of freedom = df = n - 1 = 13  

Critical value =[tex]t\alpha /2,[/tex] df = 1.771

Margin of error

[tex]E = t\alpha/2,df \times (\frac{s}{\sqrt{n} } )\\= 1.771 \times (19.22 / \sqrt 14)[/tex]  

Margin of error = E = 9.10  

The 90% confidence interval estimate of the population mean is,  

[tex]\bar x - E < \mu < \bar x + E\\\\88.34 - 9.10 < \mu < 88.34 + 9.10\\\\79.24 < \mu < 97.44\\(79.24 , 97.44)[/tex]

Answer:

[tex]\sum_{n = 1} 2*(-5)^{n-1}[/tex]

Step-by-step explanation:

An arithmetic sequence is of the form:

[tex]A_n = A_{n-1} + d[/tex]

While a geometric sequence is of the form:

[tex]A_n = A_{n-1}*r[/tex]

notice that first, we have a change of sign in our sequence, so we already can discard the arithmetic sequence.

In fact, the pattern is kinda easy to see.

The first term is:

A₁ = 2

the second term is:

A₂ = -10

notice that:

A₂/A₍ = r = -10/2 = -5

The third term is:

A₃ = 50

the quotient between the third term and the second term is:

A₃/A₂ = 50/-10 = -5

Whit this we can already conclude that the n-th term of our sequence will be:

[tex]A_n = A_{n-1}*(-5)[/tex]

Then the summation will be something like:

[tex]\sum_{n = 1} A_n = A_1 + A_2 + A_3 + ... = 2 - 10 + 50 - ...[/tex]

We can write:

[tex]A_n = A_{n-1}*(-5) = (A_{n-2}*(-5))*(-5)) = A_1*(-5)^{n-1} = 2*(-5)^{n-1}[/tex]

Then the summation is just:

[tex]\sum_{n = 1} 2*(-5)^{n-1}[/tex]

Answer:

A

Step-by-step explanation:

The correct answer is A

Answer:

one solution.. your answer is correct

Step-by-step explanation:

discriminate = 900 - (4*9*25)  = 0

thus only one solution

Supplementary angles are those angles which make a sum of 180°.

Complementary angles are those angles which make a sum of 90°.

The supplementary angles are given by the straight lines making angles of 180°.

There are two straight lines CB and DE

The angles DAF and FAE are the two angles making a straight line DE

The angles CAF and FAB are the two angles making a straight line CB

The complementary angles are given by angles formed between the perpendicular lines making angles of 90°.

Angle BAF is formed by angle BAE and angle AEF

Supplementary Angle given by the straight line DE is formed by the angles DAF and FAE.

Complementary Angle BAF is formed by angle BAE and angle AEF.

https://brainly.com/question/12919120

Answer: 1865

Step-by-step explanation:

Given

Claimed strains of virus is 1700

If it is increased by 9.7%

Estimated value can be given by

[tex]\Rightarrow 1700+1700\times 9.7\%\\\Rightarrow 1700(1+0.097)\\\Rightarrow 1700\times 1.097\\\Rightarrow 1864.9\approx 1865[/tex]

Thus, the estimated number is [tex]1865[/tex]

Answer:

each movie costs $2.75, each video game costs $6.75

Step-by-step explanation:

x = movies, y = video games

7x + 9y = 80

5x + 3y = 34

simplified to

x = 11/4 , y = 27/4

Step-by-step explanation:

I think something went wrong with the answer options you provided. and maybe with the problem statement itself.

I see 3 function definitions.

I can tell you what they are and use the provided option phrasing as closely as possible :

h(x) = 0 is a horizontal line (in fact the x-axis)

k(x) = 4x² + 312 is a parabola with the opening upwards

f(x) = x - 1 is a line with positive slope (going from left to right the line goes up)

Answer:

They are equal

Step-by-step explanation:

4.5% is 0.045 in decimal form

Answer: They are equal

Step-by-step explanation:

I always remember by taking the two o's in percent and moving them two spots to the left and vise versa if you want to make a decimal into a percent  (move it two spots to the right).

The shapes are the same size. Match the sides.

3x -1 = 17

Add 1 to both sides:

3x = 18

Divide both sides by 3:

X = 6

2y = 16

Divide both sides by 2

Y = 8

Answer: x = 6, y = 8

Step-by-step explanation:

Given, x = 5

y = 5

= 6(5)^2 +7(5)(5) +3(5)

= 6(25)+7(25) +15

= 150+175 + 15

= 150 + 190

=340

Answer:

x = 12 y = 7

Step-by-step explanation:

6x^2 + 7xy + 3y

6(5)^2+ 7(5) + 7(8)y

6(5+5)+25+35 + 7(8)-7y

60+25+35+ 56-7y

y - 5 = 120 + 35 - 5 (+49y)

sqrt 150 + sqrt 49

x = 12 y = 7

Answer:

6

Step-by-step explanation:

You have 2 conditions.

1. The digits must be different.

2. The digits must add to 7.

There aren't very many

124

142

214

241

412

421

That's it. That's your answer. There are 6 of them

Answer:

76 degrees

Step-by-step explanation:

First, we can draw a picture. Two of the sides are 110 feet and 55 feet. In a triangle, the smallest angle is opposite the smallest side and vice versa. Therefore, if I have my triangle arranged in the way shown, the smallest angle of 29 degrees will be opposite of the smallest side of 55 feet.

The law of sines states that a/sinA=b/sinB=c/sinC , with corresponding angles being opposite of its corresponding side. Therefore, we can say that

55 feet/ sin(29 degrees) = 110 / sin(largest angle).

If we say that the largest angle is equal to x, we can say

55 / sin(29°) = 110/sin(x)

multiply both sides by x to remove a denominator

55 * sin(x)/ sin(29°) = 110

multiply both sides by sin(29°) to remove the other denominator

55 * sin(x) = 110 * sin(29°)

divide both sides by 55 to isolate the sin(x)

sin(x) = 110 * sin(29°) / 55

For an angle, if sin(x) = y, we can say that arcsin(y) = x. Therefore, we can say

x = arcsin(110 * sin(29°)/55)

x ≈ 76 degrees

Answer:

x=12

Step-by-step explanation:

each side of the smaller triangle, we can multiply by 4 to get the side of the larger triangle

ex: 8*4=32 and 17*4=68

so we can assume that 15*4= 4x+12

60=4x+12

48=4x

x=12

Answer:

x = 12

Step-by-step explanation:

The triangles are similar so we can use ratios

4x+12      32

-------  = ------------

15             8

Using cross products

(4x+12) *8 = 15 * 32

(4x+12) *8 = 480

Divide each side by 8

(4x+12) *8/8 = 480/8

4x+12 = 60

Subtract 12 from each side

4x+12 -12 = 60-12

4x = 48

Divide by 4

4x/4 = 48/4

x = 12

Step-by-step explanation:

The answer is 5/8 + 1/3

Answer = 5*3 /(8*3) +8/24 =23/24

Answer = 23/24

Answer:

8

Step-by-step explanation:

11 + x = 19

Subtract 11 from each side

11+x -11 = 19-11

x = 8

Answer:

8

Step-by-step explanation:

11 + box = 19

=> box = 19 - 11

.°. box = 8

Answer:

Answered March 20, 2021

This is a right angle triangle where the hypotenuse a^2 = b^2 + c^2

= 15^2 + 8^2 = 225+64= 289

289= 17^2

17 = hypotenuse

The sine of an angle is the ratio of the shortest side to the hypotenuse

= 8/17= 0.4705

sine^-1 0.4705 = 28°

Answer:

1. 0.0910 = 9.10% probability that exactly 180 passengers show up for the flight.

2. 0.4522 = 45.22% probability that at most 180 passengers show up for the flight.

3. 0.5478 = 54.78% probability that more than 180 passengers show up for the flight.

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

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]

Normal probability distribution

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

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that [tex]\mu = E(X)[/tex], [tex]\sigma = \sqrt{V(X)}[/tex].

Assume that there is a 0.905 probability that a passenger with a ticket will show up for the  flight.

This means that [tex]p = 0.905[/tex]

Also assume that the airline sells 200 tickets

This means that [tex]n = 200[/tex]

Question 1:

Exactly, so we can use the P(X = x) formula, to find P(X = 180).

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 180) = C_{200,180}.(0.905)^{180}.(0.095)^{20} = 0.0910[/tex]

0.0910 = 9.10% probability that exactly 180 passengers show up for the flight.

2. When 200 tickets are sold, calculate the probability that at most 180 passengers show up for the flight.

Now we have to use the approximation.

Mean and standard deviation:

[tex]\mu = E(X) = np = 200*0.905 = 181[/tex]

[tex]\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{200*0.905*0.095} = 4.15[/tex]

Using continuity correction, this is [tex]P(X \leq 180 + 0.5) = P(X \leq 180.5)[/tex], which is the p-value of Z when X = 180.5. Thus

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

[tex]Z = \frac{180.5 - 181}{4.15}[/tex]

[tex]Z = -0.12[/tex]

[tex]Z = -0.12[/tex] has a p-value of 0.4522.

0.4522 = 45.22% probability that at most 180 passengers show up for the flight.

3. When 200 tickets are sold, calculate the probability that more than 180 passengers show up for the flight.

Complementary event with at most 180 passengers showing up, which means that the sum of these probabilities is 1. So

[tex]p + 0.4522 = 1[/tex]

[tex]p = 1 - 0.4522 = 0.5478[/tex]

0.5478 = 54.78% probability that more than 180 passengers show up for the flight.