The area of a square is increasing at a rate of 2 square feet a second. If the square started with an area of 4 square feet, how much time passes before the area of the square equals 16 square feet

Answer:x>-1

Step-by-step explanation:

Step 1: Subtract 3 from both sides.

-3x+3-3<6-3

-3x<3

Step 2: Divide both sides by -3.

-3x/-3<3/3

X>-1

Answer:

a) The volume of the wooden block is 240 cm^3.

b) The density of the wooden block is 0.7 g/cm^3.

Step-by-step explanation:

The volume of the rectangular wooden block can be calculated as the multiplication of the length in each dimension: length, wide and height.

With dimensions 10 cm x 3 cm x 8 cm, the volume is:

[tex]V=L\cdot W\cdot H = 10\cdot 3\cdot 8=240[/tex]

The volume of the wooden block is 240 cm^3.

If we know that the mass of the wooden block is 168 g, we can calculate the density as:

[tex]\rho = \dfrac{M}{V}=\dfrac{168}{240}=0.7[/tex]

The density of the wooden block is 0.7 g/cm^3.

Answer:

see below

Step-by-step explanation:

You can remove one or more of the other color marbles to increase the probability of drawing a green marble

or

You can add  one or more green marbles to have more green marbles in the bag

Answer:

The length of the short side is 14.5 units, the length of the other short side is 18.5 units, and the length of the longest side is 23.5 units.

Step-by-step explanation:

The Pythagorean Theorem

If a and b are the lengths of the legs of a right triangle and c is the length of the hypotenuse, then the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse.

This relationship is represented by the formula:

                                                     [tex]a^2+b^2=c^2[/tex]

Applying the Pythagorean Theorem  to find the lengths of the three sides we get:

[tex](x)^2+(x+4)^2=(x+9)^2\\\\2x^2+8x+16=x^2+18x+81\\\\2x^2+8x-65=x^2+18x\\\\2x^2-10x-65=x^2\\\\x^2-10x-65=0[/tex]

Solve with the quadratic formula

[tex]\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}[/tex]

[tex]x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]

[tex]\mathrm{For\:}\quad a=1,\:b=-10,\:c=-65:\quad x_{1,\:2}=\frac{-\left(-10\right)\pm \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}\\\\x_{1}=\frac{-\left(-10\right)+ \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5+3\sqrt{10}\\\\x_{2}=\frac{-\left(-10\right)- \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5-3\sqrt{10}[/tex]

Because a length can only be positive, the only solution is

[tex]x=5+3\sqrt{10}\approx 14.5[/tex]

The length of the short side is 14.5, the length of the other short side is [tex]14.5+4=18.5[/tex], and the length of the longest side is [tex]14.5+9=23.5[/tex].

Answer:

The probability that at exactly one of them does exactly two language classes is 0.32.

Step-by-step explanation:

We can model this variable as a binomial random variable with sample size n=2.

The probability of success, meaning the probability that a student is in exactly two language classes can be calculated as the division between the number of students that are taking exactly two classes and the total number of students.

The number of students that are taking exactly two classes is equal to the sum of the number of students that are taking two classes, minus the number of students that are taking the three classes:

[tex]N_2=F\&S+S\&G+F\&G-F\&S\&G=12+4+6-2=20[/tex]

Then, the probabilty of success p is:

[tex]p=20/100=0.2[/tex]

The probability that k students are in exactly two classes can be calcualted as:

[tex]P(x=k) = \dbinom{n}{k} p^{k}(1-p)^{n-k}\\\\\\P(x=k) = \dbinom{2}{k} 0.2^{k} 0.8^{2-k}\\\\\\[/tex]

Then, the probability that at exactly one of them does exactly two language classes is:

[tex]P(x=1) = \dbinom{2}{1} p^{1}(1-p)^{1}=2*0.2*0.8=0.32\\\\\\[/tex]

Answer:

The answer is Y = 6.3973.

Note: Kindly find an attached document of the complete question to this solution

Sources: The complete question was researched from Quizlet site.

Step-by-step explanation:

Solution

Given that:

The regression  equation is given below:

Y = - 0.3302 + 0.0672 x₁ + 0.6735 x₂ + 0.9980 x₃

Now,

When x₂ = 5, x₁ = 50, x₃ = 0

Y = - 0.3302 + 0.0672 * 50 +0.6735 * 5

Y=  - 0.3302 + 3.36 + 3.3675

Y = 6.3973

Therefore the time (hour) it will take for the driver to make five deliveries on a 50 mile journey not during rush hour is 6.3973.

Answer:

Option B

Step-by-step explanation:

The number that had never been married will vary in each sample due to the random selection of adults.

This number will vary in each sample to the random selection process but they might or might not be as close as possible to one another after sampling.

Answer:

y = 1/2x + 1

Step-by-step explanation:

Step 1: Find slope

(1-0)/(0+2) = 1/2

Step 2: Write equation

y = 1/2x + 1

Answer:

b) -1/9

Step-by-step explanation:

Given

              [tex]a_{n} = \frac{(-1)^{n} }{2n-1}[/tex]

First term

              [tex]a_{1} = \frac{(-1)^{1} }{2(1)-1} = -1[/tex]

second term

            [tex]a_{2} = \frac{(-1)^{2} }{2(2)-1} = \frac{1}{3}[/tex]

Third term

           [tex]a_{3} = \frac{(-1)^{3} }{2(3)-1} = \frac{-1}{5}[/tex]

Fourth term

          [tex]a_{4} = \frac{(-1)^{4} }{2(4)-1} = \frac{1}{7}[/tex]

Fifth term

         [tex]a_{5} = \frac{(-1)^{5} }{2(5)-1} = \frac{-1}{9}[/tex]

Answer:

B

Step-by-step explanation:

right on edge 2021

Answer:

See the answers below.

Step-by-step explanation:

[tex]a.\:\frac{f\left(x\right)-f\left(a\right)}{x-a}=\frac{2x^2-x-5-\left(2a^2-a-5\right)}{x-a}\\\\=\frac{2x^2-x+a-2a^2}{x-a}\\\\=\frac{2\left(x+a\right)\left(x-a\right)-1\left(x-a\right)}{x-a}\\\\=\frac{\left(x-a\right)\left[2\left(x+a\right)-1\right]}{x-a}\\\\=2x+2a-1\\\\\\b.\:\frac{f\left(x+h\right)-f\left(x\right)}{h}=\frac{2\left(x+h\right)^2-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\\\=\frac{2\left(x^2+2xh+h^2\right)-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\[/tex]

Expand and simplify to get:

[tex]=\frac{2h^2+4xh-h}{h}\\\\=\frac{h\left(2h+4x-1\right)}{h}\\\\=2h+4x-1[/tex]

Best Regards!

Answer:

  56.25°

Step-by-step explanation:

The definition of the cosine function tells you that

  cos(B) = BC/BA

  B = arccos(BC/BA) = arccos(5/9)

  B ≈ 56.25°

Answer:

Option B

Step-by-step explanation:

<r = 32 degrees (alternate angles )

<r = <n = 32 degrees (vertical angles)

Answer:

the correct choice is A. At the gas station

Step-by-step explanation:

Lucy starts at home and travels 3 miles south to the post office. From the post office, she travels 4 miles east to the gas station. As it is known south and east directions form right angle. Since the entire trip forms a triangle, this triangle is right with right angle at the post office.

Call the vertices of this triangle P - post office, G - gas station, H - home. Then HP and PG are legs of this triangle and GH is hypotenuse.

From the given data:

HP=3;

PG=4;

GH=5;

∠P=90°.

The smallest angle is opposite to the smallest side. The smallest side is leg HP, so the smallest angle is G that is the angle at gas station.

Answer:

a

Step-by-step explanation:

9.8 +12x+y-7

2.8+12x+4y

Answer:

2*2  * 2*2   * 2*3

Step-by-step explanation:

96 =16 *6

Break these down, since neither 16 nor 6 are prime

    = 4*4 * 2*3

4 in not prime, but 2 and 3 are prime

   = 2*2  * 2*2   * 2*3

All of these are prime

Answer:

22, 23

Step-by-step explanation:

Just got it right on edge 2021

Answer:

Unit rate = 81  riders/ car.

Step-by-step explanation:

Given

729 riders in 9 cars

we have to find unit rate in terms of riders per car

let the the riders per car (i.e rate) be x.

If there are 9 cars then

total no. of riders in 9 cars = no. of cars *  riders per car = 9*x = 9x

given that 729 riders in 9 cars

then

9x = 729

=> x = 729/9 = 81

Thus, riders per car =  x = 81.

Unit rate is 81 riders per car.

Answer: He would need at least a 95

Step-by-step explanation:

First I found the current average by adding 72, 74, 89, and 90 which equals 325.

Second, I worked backwards to see what the sum of his grades had to be by multiplying 84 times 5. 84 times 5 = 420

Now that we have both the current and the target sum, we find the difference by doing 420-325 which equals 95.

Answer:

[tex]distance=\sqrt{32}[/tex]  , which agrees with answer "c" in your list of possible options

Step-by-step explanation:

Use the formula for distance between two points [tex](x_1,y_1)[/tex], and [tex](x_2,y_2)[/tex] on the plane:

[tex]distance = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2} \\distance= \sqrt{(4-8)^2+(-7-(-3))^2} \\distance= \sqrt{(-4)^2+(-4)^2} \\distance=\sqrt{16+16}\\distance=\sqrt{32}[/tex]

Answer:

[tex]-p^4+4p^3-5p^2+8p-6[/tex]

I hope this help you :)

Answer: 267.9

Step-by-step explanation:

Since we are given the radius, we can plug it into the equation given.

[tex]V=\frac{4}{3} \pi (4)^3[/tex]

[tex]V=\frac{4}{3} \pi (64)[/tex]

[tex]V=267.9[/tex]

Answer:

The number of employees classified into groups as shown below:

1 - 10: 3 6 (2companies)

11-20: 16 (1 company)

21-30: 25, 26, 27 (3 companies)

31-40: 34, 35, 35, 35, 36 (5 companies)

41-50: 41, 43, 48, 48 (4 companies)

Hope this helps!

Answer:

11-20 is 1

31-40 is 5

Step-by-step explanation:

Just count the amount

Hope that helps :D

Answer:

(a)

[tex]Slope=-\dfrac{1}{3}\\$y-intercept =1[/tex]

(b)

[tex]Slope = \dfrac12\\$y-intercept=$ -1[/tex]

Step-by-step explanation:

Given a line which goes through the points: (0, 1) and (3, 0).

(a)Slope

[tex]m=\dfrac{0-1}{3-0}\\m=-\dfrac{1}{3}[/tex]

The slope-intercept form of the equation of a line is given as: y=mx+b

Therefore:

[tex]y=-\dfrac{1}{3}x+b\\$From the point (0,1), When x=0, y=1; Therefore:$\\1=-\dfrac{1}{3}(0)+b\\$Therefore:\\b=1[/tex]

The y-intercept of the line through points (0, 1) and (3, 0) is 1.

(b)Given the line:

[tex]y=\dfrac12x-1[/tex]

Comparing with the slope-intercept form of the equation of a line: y=mx+b

[tex]Slope = \dfrac12\\$y-intercept=$ -1[/tex]

Answer:

Identify the slope of the graphed line:

✔ -1/3

Identify the y-intercept of the graphed line:

✔ 1

Identify the slope of the line given by the equation:

✔ 1/2

Identify the y-intercept of the line given by the equation:

✔ -1

Step-by-step explanation:

Got it right on edge. 2020

:)) hope I helped.

Answer:

(a) The standard error of the mean is 0.091.

(b) The probability that the sample mean will be less than $7.75 is 0.0107.

(c) The probability that the sample mean will be less than $8.10 is 0.9369.

(d) The probability that the sample mean will be more than $8.20 is 0.0043.

Step-by-step explanation:

We are given that the average price for a movie in the United States in 2012 was $7.96.

Assume the population standard deviation is $0.50 and that a sample of 30 theaters was randomly selected.

Let [tex]\bar X[/tex] = sample mean price for a movie in the United States

The z-score probability distribution for the sample mean is given by;

                              Z  =  [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]  ~ N(0,1)

where,  [tex]\mu[/tex] = population mean price for a movie = $7.96

            [tex]\sigma[/tex] = population standard deviation = $0.50

            n = sample of theaters = 30

(a) The standard error of the mean is given by;

     Standard error  =  [tex]\frac{\sigma}{\sqrt{n} }[/tex]  =  [tex]\frac{0.50}{\sqrt{30} }[/tex]

                                =  0.091

(b) The probability that the sample mean will be less than $7.75 is given by = P([tex]\bar X[/tex] < $7.75)

  P([tex]\bar X[/tex] < $7.75) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{7.75-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < -2.30) = 1 - P(Z [tex]\leq[/tex] 2.30)

                                                         = 1 - 0.9893 = 0.0107

The above probability is calculated by looking at the value of x = 2.30 in the z table which has an area of 0.9893.

(c) The probability that the sample mean will be less than $8.10 is given by = P([tex]\bar X[/tex] < $8.10)

  P([tex]\bar X[/tex] < $8.10) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{8.10-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < 1.53) = 0.9369

The above probability is calculated by looking at the value of x = 1.53 in the z table which has an area of 0.9369.

(d) The probability that the sample mean will be more than $8.20 is given by = P([tex]\bar X[/tex] > $8.20)

  P([tex]\bar X[/tex] > $8.20) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] > [tex]\frac{8.20-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z > 2.63) = 1 - P(Z [tex]\leq[/tex] 2.63)

                                                         = 1 - 0.9957 = 0.0043

The above probability is calculated by looking at the value of x = 2.63 in the z table which has an area of 0.9957.

Answer:

[tex]m ^ {3/7}[/tex]

Step-by-step explanation:

=> [tex]\sqrt[7]{m^3}[/tex]

[tex]\sqrt[7]{}= ^\frac{1}{7}[/tex]

=> [tex]m^{3*1/7}[/tex]

=> [tex]m ^ {3/7}[/tex]

Answer:

a) 0.9332 = 93.32% drink 2 cups per day or more.

b) 0.8413 = 84.13% drink no more than 4 cups per day

c) The minimum number of cups consumed by a heavy coffee drinker is 4.52.

d) 86.86% probability that the mean number of cups per day is greater than 3

Step-by-step explanation:

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

Normal probability distribution

When the distribution is normal, we use 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.

Central Limit Theorem

The Central Limit Theorem estabilishes 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.

In this question, we have that:

[tex]\mu = 3.2, \sigma = 0.8[/tex]

a. What proportion drink 2 cups per day or more?

This is 1 subtracted by the pvalue of Z when X = 2. So

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

[tex]Z = \frac{2 - 3.2}{0.8}[/tex]

[tex]Z = -1.5[/tex]

[tex]Z = -1.5[/tex] has a pvalue of 0.0668

1 - 0.0668 = 0.9332

0.9332 = 93.32% drink 2 cups per day or more.

b. What proportion drink no more than 4 cups per day?

This is the pvalue of Z when X = 4.

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

[tex]Z = \frac{4 - 3.2}{0.8}[/tex]

[tex]Z = 1[/tex]

[tex]Z = 1[/tex] has a pvalue of 0.8413

0.8413 = 84.13% drink no more than 4 cups per day

c. If the top 5% of coffee drinkers are considered "heavy" coffee drinkers, what is the minimum number of cups consumed by a heavy coffee drinker?

This is the 100 - 5 = 95th percentile, which is X when Z has a pvalue of 0.95. So X when Z = 1.645. Then

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

[tex]1.645 = \frac{X - 3.2}{0.8}[/tex]

[tex]X - 3.2 = 1.645*0.8[/tex]

[tex]X = 4.52[/tex]

The minimum number of cups consumed by a heavy coffee drinker is 4.52.

d. If a sample of 20 men is selected, what is the probability that the mean number of cups per day is greater than 3?

Sample of 20, so applying the central limit theore with n = 20, [tex]s = \frac{0.8}{\sqrt{20}} = 0.1789[/tex]

This probability is 1 subtracted by the pvalue of Z when X = 3.

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

By the Central Limit Theorem

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

[tex]Z = \frac{3 - 3.2}{0.1789}[/tex]

[tex]Z = -1.12[/tex]

[tex]Z = -1.12[/tex] has a pvalue of 0.1314

1 - 0.1314 = 0.8686

86.86% probability that the mean number of cups per day is greater than 3

Answer:

-45/2 - 12/2 = -57/2

Step-by-step explanation:

Substitute 15 for x in the given equation:  y = (-3/2)x - 6 becomes

y = (-3/2)(15) - 6 = -45/2  -  6 when x = 15.  This is equivalent to -57/2

Answer:

P(F | D) = 47.26%

There is a 47.26% probability that the foreman forgot to shut off the machine the previous night.

Step-by-step explanation:

A foreman for an injection-molding firm admits that on 23% of his shifts, he forgets to shut off the injection machine on his line.

Let F denote the event that foreman forgets to shut off the machine.

Failure to shut down at night causes the machine to overheat, increasing the probability that a defective molding will be produced during the early morning run from 5% to 15%.

Let D denote the event that the mold is defective.

If the foreman forgets to shut off the machine then 15% molds get defective.

P(F and D) = 0.23×0.15

P(F and D) = 0.0345

If the foreman doesn't forget to shut off the machine then 5% molds get defective.

P(F' and D) = (1 - 0.23)×0.05

P(F' and D) = 0.77×0.05

P(F' and D) = 0.0385

The probability that the mold is defective is

P(D) = P(F and D) + P(F' and D)

P(D) = 0.0345 + 0.0385

P(D) = 0.073

The probability that the foreman forgot to shut off the machine the previous night is given by

∵ P(B | A) = P(A and B)/P(A)

For the given case,

P(F | D) = P(F and D)/P(D)

Where

P(F and D) = 0.0345

P(D) = 0.073

So,

P(F | D) = 0.0345/0.073

P(F | D) = 0.4726

P(F | D) = 47.26%

Answer:

n =32

Step-by-step explanation:

If 1 contestant is eliminated each round

then of 1024contestants

32 left

1024/32=32

Answer:

n=32

Step-by-step explanation:

Step-by-step explanation:

y=7x-10

Answer:

[tex]\huge \boxed{y=7x-10}[/tex]

Step-by-step explanation:

[tex]-7x+y=-10[/tex]

[tex]\sf Add \ 7x \ on \ both \ sides.[/tex]

[tex]-7x+y+7x=-10+7x[/tex]

[tex]y=7x-10[/tex]

Answer:

a) The probability that a student will do homework regularly and also pass the course = P(H n P) = 0.57

b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P') = 0.12

c) The two events, pass the course and do homework regularly, aren't mutually exclusive. Check Explanation for reasons why.

d) The two events, pass the course and do homework regularly, aren't independent. Check Explanation for reasons why.

Step-by-step explanation:

Let the event that a student does homework regularly be H.

The event that a student passes the course be P.

- 60% of her students do homework regularly

P(H) = 60% = 0.60

- 95% of the students who do their homework regularly generally pass the course

P(P|H) = 95% = 0.95

- She also knows that 85% of her students pass the course.

P(P) = 85% = 0.85

a) The probability that a student will do homework regularly and also pass the course = P(H n P)

The conditional probability of A occurring given that B has occurred, P(A|B), is given as

P(A|B) = P(A n B) ÷ P(B)

And we can write that

P(A n B) = P(A|B) × P(B)

Hence,

P(H n P) = P(P n H) = P(P|H) × P(H) = 0.95 × 0.60 = 0.57

b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P')

From Sets Theory,

P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1

P(H n P) = 0.57 (from (a))

Note also that

P(H) = P(H n P') + P(H n P) (since the events P and P' are mutually exclusive)

0.60 = P(H n P') + 0.57

P(H n P') = 0.60 - 0.57

Also

P(P) = P(H' n P) + P(H n P) (since the events H and H' are mutually exclusive)

0.85 = P(H' n P) + 0.57

P(H' n P) = 0.85 - 0.57 = 0.28

So,

P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1

Becomes

0.03 + 0.28 + 0.57 + P(H' n P') = 1

P(H' n P') = 1 - 0.03 - 0.57 - 0.28 = 0.12

c) Are the events "pass the course" and "do homework regularly" mutually exclusive? Explain.

Two events are said to be mutually exclusive if the two events cannot take place at the same time. The mathematical statement used to confirm the mutual exclusivity of two events A and B is that if A and B are mutually exclusive,

P(A n B) = 0.

But, P(H n P) has been calculated to be 0.57, P(H n P) = 0.57 ≠ 0.

Hence, the two events aren't mutually exclusive.

d. Are the events "pass the course" and "do homework regularly" independent? Explain

Two events are said to be independent of the probabilty of one occurring dowant depend on the probability of the other one occurring. It sis proven mathematically that two events A and B are independent when

P(A|B) = P(A)

P(B|A) = P(B)

P(A n B) = P(A) × P(B)

To check if the events pass the course and do homework regularly are mutually exclusive now.

P(P|H) = 0.95

P(P) = 0.85

P(H|P) = P(P n H) ÷ P(P) = 0.57 ÷ 0.85 = 0.671

P(H) = 0.60

P(H n P) = P(P n H)

P(P|H) = 0.95 ≠ 0.85 = P(P)

P(H|P) = 0.671 ≠ 0.60 = P(H)

P(P)×P(H) = 0.85 × 0.60 = 0.51 ≠ 0.57 = P(P n H)

None of the conditions is satisfied, hence, we can conclude that the two events are not independent.

Hope this Helps!!!