Answer:
The volume is increasing at a rate of 27093 cubic inches per second.
Step-by-step explanation:
Volume of a cone:
THe volume of a cone, with radius r and height h, is given by:
[tex]V = \frac{1}{3} \pi r^2h[/tex]
In this question:
We have to differentiate implictly is function of t, so the three variables, V, r and h, are differenciated. So
[tex]\frac{dV}{dt} = \frac{\pi r^2}{3}\frac{dh}{dt} + \frac{2\pi rh}{3}\frac{dr}{dt}[/tex]
The radius of a right circular cone is increasing at a rate of 1.4 in/s while its height is decreasing at a rate of 2.4 in/s.
This means that [tex]\frac{dr}{dt} = 1.4, \frac{dh}{dt} = -2.4[/tex]
Radius is 140 in. and the height is 186 in.
This means that [tex]r = 140, h = 186[/tex]
At what rate is the volume of the cone changing?
[tex]\frac{dV}{dt} = \frac{\pi r^2}{3}\frac{dh}{dt} + \frac{2\pi rh}{3}\frac{dr}{dt}[/tex]
[tex]\frac{dV}{dt} = \frac{\pi (140)^2}{3}(-2.4) + \frac{2\pi 140*186}{3}1.4[/tex]
[tex]\frac{dV}{dt} = -0.8\pi(140)^2 + 62*2\pi*1.4*140[/tex]
[tex]\frac{dV}{dt} = 27093[/tex]
Positive, so increasing.
The volume is increasing at a rate of 27093 cubic inches per second.
The width of a rectangular slab of concrete is 7 m less than the length. The area is 98 m squared. Find the dimensions
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.
using the 1 to 9 at the most time each, fill in the boxes to make a true statement
Answer:
2
Step-by-step explanation:
8*8 is 64
Since it looks like the empty box is an exponent, and there are 2 8s being multiplied, the answer is 2
HELPPP
3p-4-8p<-19
i need the steps as well
9514 1404 393
Answer:
p > 3
Step-by-step explanation:
3p -4 -8p < -19 . . . . . . given
-5p -4 < - 19 . . . . . . . . collect terms
-5p < -15 . . . . . . . . . . . add 4
p > 3 . . . . . . . . . . . . . . divide by -5 (reverses the inequality symbol)
Juan and Lizette rented a car for one week to drive from Phoenix to Boise. The car rental rate was $250 per week and $0.20 per mile. By the most direct route, the drive is 926 miles. How much did they spend on the rental car?
( solution at pic)
4x-1,9x-1,7x-3 find the perimeter
20x-5
Answer:
Solution given;
perimeter=sum of all sides
=4x-1+9x-1+7x-3=20x-5
The perimeter of the line segments 4x - 1, 9x - 1, and 7x - 3 is 20x - 5.
To find the perimeter of the given line segments, you need to add up the lengths of all the line segments.
The lengths of the line segments are:
4x - 1,
9x - 1,
7x - 3.
To find the perimeter, add these lengths together:
Perimeter = (4x - 1) + (9x - 1) + (7x - 3)
= 4x + 9x + 7x - 1 - 1 - 3
= 20x - 5.
Therefore, the perimeter of the line segments 4x - 1, 9x - 1, and 7x - 3 is 20x - 5.
To learn more on Perimeter click:
https://brainly.com/question/7486523
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1. The area of a square is less than 25cm2. What can we say about
a. The length of one of its sides?
b. Its perimeter?
Step-by-step explanation:
Let us take a nominal square of area 25 cm².
It's length of one of it's sides will be √25 = 5 cm².It's perimeter will be 5*4 = 20 cm.So, in this question, we can say that:-
a. The length of one of its sides will be less than 5 cm.
b. Its perimeter will be less than 20 cm.
Hope it helps :)
Step-by-step explanation:
area= 25cm squared
length of one side = 5cm as 5*5 =25
perimeter= 5*4= 20cm
But since the area is less than 25cm squared
we can say that the length of one side is less than 5cm and we can also say that the length of the perimeter is less than 20cm.
Hope this helps.
hey Plz help me fast it's important.
Answer:
Step-by-step explanation:
a) 52 is divisible by 4 and 5 - 2 = 3
b) 63 is divisible by 9 and 3*2 = 6 -> ten digit
c) 50 is divisible by 10 and 5 + 0 = 5
d) 72 is divisible by 6 and 7*2 = 14
19. In a random sample of 250 students, we found that 75 work out 4 or more times a week. Find the 95% confidence interval for the proportion of students who work out 4 or more times a week.
Answer:
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
In a random sample of 250 students, we found that 75 work out 4 or more times a week.
This means that [tex]n = 250, \pi = \frac{75}{250} = 0.3[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 - 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.2432[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 + 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.3568[/tex]
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
rewrite 1/6 and 2/11 so they have a common denominator then use <, =, or > to order
Answer:
1/6 < 2/11
Step-by-step explanation:
1/6 = 2/12
2/11 >2/12
So that means 1/6 < 2/11
Answer: 1/6 < 2/11
This is the same as saying 11/66 < 12/66
===========================================================
Explanation:
1/6 is the same as 11/66 when multiplying top and bottom by 11.
2/11 is the same as 12/66 when multiplying top and bottom by 6.
The 6 and 11 multipliers are from the original denominators (just swapped).
We can see that 11/66 is smaller than 12/66, simply because 11 < 12, so that means 1/6 is smaller than 2/11
-----------------
Here's one way you could list out the steps
11 < 12
11/66 < 12/66
1/6 < 2/11
------------------
Here's another way to list out the steps. First assume that 1/6 and 2/11 are equal. Cross multiplication then leads to
1/6 = 2/11
1*11 = 6*2
11 = 12
Which is false. But we can fix this by replacing every equal sign with a less than sign
1/6 < 2/11
1*11 < 6*2
11 < 12
---------------------
Yet another way to see which is smaller is to use your calculator or long division to find the decimal form of each value
1/6 = 0.1667 approximately
2/11 = 0.1818 approximately
We see that 0.1667 is smaller than 0.1818, which must mean 1/6 is smaller than 2/11.
Javier volunteers in community events each month. He does not do more than five events in a month. He attends exactly five events 25% of the time, four events 30% of the time, three events 20% of the time, two events 15% of the time, one event 5% of the time, and no events 5% of the time. Find the probability that Javier volunteers for less than three events each month. P (x < 3) = 2 Find the expected number of events Javier volunteers in a month. 3.6 It is given that x must be below a certain value, which limits the rows to use in the PDF table. What is the sum of the probabilities of those rows?
Answer:
[tex]P(x < 3) = 25\%[/tex]
[tex]E(x) = 3[/tex]
Step-by-step explanation:
The given parameters can be represented as:
[tex]\begin{array}{ccccccc}x & {5} & {4} & {3} & {2} & {1}& {0} & P(x) & {25\%} & {30\%} & {20\%} & {15\%} & {5\%} & {5\%} \ \end{array}[/tex]
Solving (a): P(x < 3)
This is calculated as:
[tex]P(x < 3) = P(x = 0) + P(x = 1) + P(x =2)[/tex] ----- i.e. all probabilities less than 3
So, we have:
[tex]P(x < 3) = 5\% + 5\% + 15\%[/tex]
[tex]P(x < 3) = 25\%[/tex]
Solving (b): Expected number of events
This is calculated as:
[tex]E(x) = \sum x * P(x)[/tex]
So, we have:
[tex]E(x) = 5 * 25\% + 4 * 30\% + 3 * 20\% + 2 * 15\% + 1 * 5\% + 0 * 5\%[/tex]
[tex]E(x) = 125\% + 120\% + 60\% + 30\% + 5\% + 0\%[/tex]
[tex]E(x) = 340\%[/tex]
Express as decimal
[tex]E(x) = 3.40[/tex]
Approximate to the nearest integer
[tex]E(x) = 3[/tex]
A hotel manager believes that 23% of the hotel rooms are booked. If the manager is right, what is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%
Answer:
0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less 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
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]
A hotel manager believes that 23% of the hotel rooms are booked.
This means that [tex]p = 0.23[/tex]
Sample of 610 rooms
This means that [tex]n = 610[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.23[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.23*0.77}{610}} = 0.017[/tex]
What is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%?
p-value of Z when X = 0.23 + 0.03 = 0.26 subtracted by the p-value of Z when X = 0.23 - 0.03 = 0.2. So
X = 0.26
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.26 - 0.23}{0.017}[/tex]
[tex]Z = 1.76[/tex]
[tex]Z = 1.76[/tex] has a p-value of 0.9608
X = 0.2
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.2 - 0.23}{0.017}[/tex]
[tex]Z = -1.76[/tex]
[tex]Z = -1.76[/tex] has a p-value of 0.0392
0.9608 - 0.0392 = 0.9216
0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%
In a survey, 24 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $42 and standard deviation of $2. Construct a confidence interval at a 98% confidence level.
Answer:
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 24 - 1 = 23
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 23 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.98}{2} = 0.99[/tex]. So we have T = 2.5
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.5\frac{2}{\sqrt{24}} = 1.02[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.02 = $40.98.
The upper end of the interval is the sample mean added to M. So it is 42 + 1.02 = $43.02.
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
If F is the function defined by F(x)=3x−1, find the solution set for F(x)=0.
The solution for set F(x) is -1
solve 5x^2-2=-12 by taking the square root
Answer:
x = ±i√2
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightEquality Properties
Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtraction Property of Equality
Algebra II
Imaginary root i
i = √-1Step-by-step explanation:
Step 1: Define
Identify
5x² - 2 = -12
Step 2: Solve for x
[Addition Property of Equality] Add 2 on both sides: 5x² = -10[Division Property of Equality] Divide 5 on both sides: x² = -2[Equality Property] Square root both sides: x = ±√-2Rewrite: x = ±√-1 · √2Simplify: x = ±i√2Which statement best describes g(x) = 3x + 6 - 8 and the parent function f(x) = } ?
The domains of g(x) and f(x) are the same, but their ranges are not the same.
* The ranges of g(x) and f(x) are the same, but their domains are not the same.
The ranges of g(x) and f(x) are the same, and their domains are also the same.
The domains of g(x) and f(x) are the not the same, and their ranges are also not the same.
Answer:
In general gf(x) is not equal to fg(x)
Some pairs of functions cannot be composed. Some pairs of functions can be composed only for certain values of x.
Only with they can be composed some values of x are the ranges of g(x) and f(x) are the same, and their domains are also the same. Or else lies inside it.
Step-by-step explanation:
g(x) = 3x + 6 - 8, f(x) = √x.
The domain of a composed function is either the same as the domain of the first function, or else lies inside it
The range of a composed function is either the same as the range of the second function, or else lies inside it.
Or vice versa
Now only positive numbers, or zero, have real square roots. So g is defined only for numbers
greater than or equal to zero. Therefore g(f(x)) can have a value only if f(x) is greater than or
equal to zero. You can work out that
f(x) ≥ 0 only when x ≥3/2
.
Question A cotton farmer produced 390 pounds per acre after 4 years of operating. After 9 years, he was producing 460 pounds per acre. Assuming that the production amount has been increasing linearly, estimate the production per acre 7 years after he started farming. Your answer should just be a numerical value. Do not include units in your answer. Provide your answer below:
A student has test scores of 75 and 82respectively. What is the student’s average score for a third test
Answer:
78.5 (I think 90% sure)
Step-by-step explanation:
sum of both scores
75+82 = 157
average for a third test
157÷2=78.5
what are the zeroes of f(x)=(x-7)(x+8)
Answer:
The zeroes of f(x) = (x-7)(x+8) are 7 and -8.
Step-by-step explanation:
You have to figure out what makes each of the equal to zero.
Step 1 : Make the 2 equations both equal 0.
x-7 = 0
x+8 = 0
Step 2: Solve for x
x-7 = 0
x=7
x+8 = 0
x=-8
So 7 and -8 are both zeroes of this function.
Two mechanics worked on a car. The first mechanic worked for 10 hours, and the second mechanic worked for 5 hours. Together they charged a total of $1125. What was the rate charged per hour by each mechanic if the sum of the two rates was $140 per hour?
Answer:
The first mechanic charged $ 85 an hour, and the second mechanic charged $ 55 an hour.
Step-by-step explanation:
Given that two mechanics worked on a car, and the first mechanic worked for 10 hours, and the second mechanic worked for 5 hours, and together they charged a total of $ 1125, to determine what was the rate charged per hour by each mechanic if the sum of the two rates was $ 140 per hour, the following calculation must be performed:
1125/15 = X
75 = X
80 x 10 + 60 x 5 = 800 + 300 = 1100
85 x 10 + 55 x 5 = 850 + 275 = 1125
Therefore, the first mechanic charged $ 85 an hour, and the second mechanic charged $ 55 an hour.
A man had 35 goats.he sold 10 of
them.how many did he remains with.
Answer:
He remained with 25 goats.
Step-by-step explanation:
35 - 10 = 25
Hope this helps.
Answer:
He remained with 25 goats
Step-by-step explanation:
35 - 10 = 25
a car travels 10 km southeast and 15 km in a direction 60 degrees north of east. find the magnitude and direction
Answer:
the car travels 10km then 15km 60* north of east
Step-by-step explanation:
A game-show spinner has these odds of stopping on particular dollar values: 55% for $5, 20% for $25, 15% for $50, and 10% for $500. What are the odds of a player winning $5 or $25
Answer: 75%
Step-by-step explanation:
HELP PLEASE! I tried everything from adding to dividing, subtracting, multiplying but still no correct answer. Can someone help me out here please? I am not sure where to start. Thank you for your time.
Answer:
6.09 is the answer rounded to nearest hundredths.
Step-by-step explanation:
It gives you n=150, p=0.55, and q=1-p.
If p=0.55 and q=1-p, then by substitution property we have q=1-0.55=0.45.
It ask you to evaluate the expression sqrt(npq).
So npq means find the product of 150 and 0.55 and 0.45. So that is 150(0.55)(0.45)=37.125.
The sqrt(npq) means we need to find the square root of that product. So sqrt(37.125)=6.093 approximately .
HELP! AAHHHHH SOMEBODY HELP!
If each square of the grid below is $0.5\text{ cm}$ by $0.5\text{ cm}$, how many square centimeters are in the area of the blue figure?
Answer:
8.50 cm²
Step-by-step explanation:
The dimension of each square is given as 0.5cm by 0.5cm
The area of the a square is, a²
Where, a = side length
Area of each square = 0.5² = 0.25cm
The number of blue colored squares = 34
The total area of the blue colored squares is :
34 * 0.25 = 8.50cm²
There is a high-speed rail track between London and Manchester.
The length of this track is 210 miles.
A train departs London at 11:20 and arrives in Manchester at 13:28
The train company claims
the average speed of this train is 104 miles per hour.
Is the average speed of this train 104 miles per hour?
(4)
Use the box below to show clearly how you get your answer.
Answer:
Step-by-step explanation:
this is the famous dirt formula, :P I made it up :D
D=rt ( notice it looks like Dirt , kinda, but it also means it dirt simple )
D= distance
r = rate ( think speed or how fast)
t = time ( in what ever units of time you want to use, seconds, minutes, hours )
13:28 - 11:20 = 128 minutes ( b/c the question is asking in MPH convert to hours) 2.4666667 hours
210 miles = r * 2.46666667
210 / 2.46666667 = r ( in MPH) ( does anyone else find it odd that they are saying miles in London instead of kilometers? :/ )
85.135 MPH = rate
so no, not even close to 104 MPH :/
Answer:
Average speed is 98 mph
Step-by-step explanation:
[tex]\frac{distance (miles)}{time (hours)}[/tex] = speed [tex]\frac{mile}{hours}[/tex] (miles per hour is a ratio)
The time is 2 hours and 8 minutes.
[tex]\frac{8}{60}[/tex] = .13333 ( 8 minutes / 60 minutes in a hour)
So time is 2.133333 hours .
Divide the distance 210 by the time 2.13333 and get the speed.
Its 98.437..
Round to 98 miles per hour.
what is the best deal for diet coke?
12oz. for $.99
64oz. for $.2.99
128oz. for $4.99
Answer:
128 for 4.99
64 for 2.99 times 2 is more than 4.99.
12 oz. for 0.99 is also more than 4.99.
Find in the triangle. Round to the nearest degree.
Answer:
D. 34
Step-by-step explanation:
Because this is a right triangle we can use sin, cos, tan.
Use cosine because the values of the adjacent side and hypotenuse are already given.
cos(θ) = 72/87
Because we are solving for the angle measure (and not the measure of the side) we need to use inverse cos.
cos⁻¹ = 72/87
put into a calculator and answer is approximatelyn34 degrees.
math help plz
how to solve parabola and its vertex, how to understand easily and step by step with an example provided please
Answer:
The general equation for a parabola is:
y = f(x) = a*x^2 + b*x + c
And the vertex of the parabola will be a point (h, k)
Now, let's find the values of h and k in terms of a, b, and c.
First, we have that the vertex will be either at a critical point of the function.
Remember that the critical points are the zeros of the first derivate of the function.
So the critical points are when:
f'(x) = 2*a*x + b = 0
let's solve that for x:
2*a*x = -b
x = -b/(2*a)
this will be the x-value of the vertex, then we have:
h = -b/(2*a)
Now to find the y-value of the vertex, we just evaluate the function in this:
k = f(h) = a*(-b/(2*a))^2 + b*(-b/(2*a)) + c
k = -b/(4*a) - b^2/(2a) + c
So we just found the two components of the vertex in terms of the coefficients of the quadratic function.
Now an example, for:
f(x) = 2*x^2 + 3*x + 4
The values of the vertex are:
h = -b/(2*a) = -3/(2*2) = -3/4
k = -b/(4*a) - b^2/(2a) + c
= -3/(4*2) - (3)^2/(2*2) + 4 = -3/8 - 9/4 + 4 = (-3 - 18 + 32)/8 = 11/8
Find the appropriate answer for each word problem.
a. A group of twelve art students are visiting a local art museum for a field trip. The total cost of admission for the students is $125. What is the cost of admission for each student?
b. The school van can carry twelve passengers at a time. What is the least number of trips the van must make in order to bring 125 passengers to the same location?
c. Charlotte and her mother baked 125 cookies to give as Christmas gifts to their neighbors. If they plan to give a dozen cookies to each neighbor, how many neighbors will receive a gift?
d. Nicholas and Elaine are planning to serve cheesecake for dessert at their wedding and have purchased twelve cheesecakes. If the cheesecakes are divided evenly among the 125 wedding guests, how much cheesecake will each guest receive?
I WILL GIVE BRAINLIEST IF CORRECT
Answer:
a. $10
b. 10.46
c. 10.46
d. 0.096
Find domain of (x^2+3)+[tex]\sqrt{x} 3x-1[/tex]
Answer:
= x^2 + 3 + √3x^2 - 1
Step-by-step explanation:
Remove parentheses: (a) = a
= x^2 + 3 + √x . 3x - 1
x . 3x = 3x^2
= x^2 + 3 + √3x^2 - 1
