Answer:
The correct answer is:
(a) Mean = 170,
Standard deviation = 30
(b) 1700
Step-by-step explanation:
Given:
n = 100μ = 2040σ = 360(a)
Mean of monthly expenses will be:
= [tex]\frac{\mu}{2}[/tex]
= [tex]\frac{2040}{2}[/tex]
= [tex]170[/tex]
Standard deviation will be:
= [tex]\frac{\sigma}{12}[/tex]
= [tex]\frac{360}{12}[/tex]
= [tex]30[/tex]
(b)
The total amount of monthly expenses will be:
= [tex]n\times \frac{\mu}{12}[/tex]
= [tex]100\times 170[/tex]
= [tex]1700[/tex]
An employment agency specializing in temporary construction help pays heavy equipment operators $123 per day and general laborers $89 per day. If thirty-one people were hired and the payroll was $3507, how many heavy equipment
operators were employed? How many laborers?
The number of heavy equipment operators hired was
The number of general laborers hired was
Answer:
The number of operators is 22 and the number of laborers is 9
Step-by-step explanation:
This is a 2 line equation system
I'll call the laborers "L" and the equipment operators "E"
The first line of the system is pretty much telling me that the number of laborers plus the number of operators is 31:
L + E = 31
Now we need to calculate the money:
Since we know that laborers are paid $89 per day we're gonna multiply them by that. Same thing with the operator, but the value is now $123
89L + 123E = 3507
Our two line system is like this:
L + E = 31
89L + 123E = 3507
We need either L or E to be the same in both of the equations so that when I subtract one from another I can find the value of one of the variables
I'll choose L cause it's the lower number, so I'll multiply the upper equation:
L+E=31 === *89 ====> 89L + 89E = 2.759
Now we have these equations:
89L + 89E = 2.759
89L + 123E = 3507
Now I'm gonna subtract the lower equation from the upper one:
89L - 89L + 123E - 89E = 3507 - 2759
Since L is now zero it disappears, and by making the other calculations we have:
34E = 748
E = 22
Since E = 22, we can use the value in our first equation:
E+L=31 ===> 22+L=31 ===> L=9
Got it! The number of operators is 22 and the number of laborers is 9.
If you wanna double check this you can calculate the amount of money they're paid, which should add up to $3507:
22 operators * $123 = $2706
9 laborers * $89 = $801
2706+801 = $3507
We're good
If this helped you at all, would it be too much asking for brainliest?
I would really appreciate it
Have a great one
class 7th chapter: Simple Equation
The solution of the equation p-1 =20 is -------- *
a) 19
b) 20
c) 21
Answer:
C
Step-by-step explanation:
p=20+1
Write an algebraic expression for the situation. 28 divided by a number n An algebraic expression for the situation is
Answer:
[tex]\frac{28}{n}[/tex]
Step-by-step explanation:
help me with these questions
Answer:
24
Step-by-step explanation:
:) im in 8th do i already know this stuff
a) Read section 1.5 in the Yakir textbook. If you were a teacher and had 30 students in your class and wanted to know the class average on the first quiz, would you use a parameter or a statistic
Answer:
Parameter
Step-by-step explanation:
Required
Parameter of Statistic
From the question, we understand that the teacher is to calculate the class average.
To calculate the class average, the teacher will use the mean function/formula, which is calculated as:
[tex]Mean = \frac{\sum x}{n}[/tex]
Generally, mean is an example of a parameter.
So, we can conclude that the teacher will use parameer
5/6 ÷ 1/3 - 2/3 (2/5)
Answer:
[tex] \frac{67}{30} \: \text{or} \:2 \frac{7}{30} [/tex]
Step-by-step explanation:
5/6 ÷ 1/3 - 2/3 (2/5)
= 5/6 ÷ 1/3 - 2/3 × 2/5= 5/2 - 2/3 × 2/5= 5/2 - 4/15= 67/30 or 2 7/30Hope it helps you! ＼(^ᴥ^)／
In a survey of 302 registered voters, 167 of them wished to see Mayor Waffleskate lose her next election. Find a point estimate for the proportion of registered voters who wish to see Mayor Waffleskate defeated.
Answer:
A point estimate for the proportion of registered voters who wish to see Mayor Waffleskate defeated is of 0.553.
Step-by-step explanation:
Point estimate:
The point estimate of a proportion is the sample proportion(number of desired outcomes divided by the number of total outcomes).
Find a point estimate for the proportion of registered voters who wish to see Mayor Waffleskate defeated.
167 out of 302. So
[tex]p = \frac{167}{302} = 0.553[/tex]
A point estimate for the proportion of registered voters who wish to see Mayor Waffleskate defeated is of 0.553.
How to solve this problem what do I do
=================================================
Explanation:
We undo the "minus 6" by adding 6 to both sides.
Also, we undo the "+s" by subtracting s from both sides
-----------
So we have these steps
P = r+s-6
P+6 = r+s-6+6 .... adding 6 to both sides
P+6 = r+s
r+s = P+6
r+s-s = P+6-s ..... subtracting s from both sides
r = P + 6 - s
Answer:
P+6-s=r
Step-by-step explanation:
Hi there!
We are given the equation P=r+s-6 and we need to solve for r
To do that, we need to isolate r onto one side, and have everything else on the other.
Here is the equation:
P=r+s-6
start by adding 6 to both sides to clear it from the right side
P+6=r+s
now subtract s from both sides to clear it from the right side
P+6-s=r
now everything that isn't r is on the left side, and r is by itself on the right side. P+6-s=r is the answer.
Hope this helps!
An office manager buys 2 office chairs and 4 file cabinets for $380. Next year she buys 4 office chairs and 6 file cabinets for $660. What is the cost of each office chair, c? What is the cost of each file cabinet, f? Explain how you fond the cost of each chair and file cabinet.
Answer:
16.5
Step-by-step explanation:
Answer:
file cabinet = 50
chair = 90
Step-by-step explanation:
x = chair
y = file cabinet
1st year, solve for x
2x+4y = 380
2x = 380 - 4y
x = 190 - 2y
2nd year
Now substitute x = 190 - 2y in your 2nd year formula
4x+6y = 660
4(190-2y)+6y = 660
760 - 8y + 6y = 660
-2y = -100
y = 50
The cost of the filling cabinet is 50 each
Now use the value for y (50) in your first formula to get x
2x+4y=380
2x+4*50=380
2x=380-200
2x=180
x=90
Instructions: Solve the following literal
equation.
Solve 4x – 2y = 18 for y.
y =
Answer:
[tex]y = - 9 + 2x[/tex]
Step-by-step explanation:
Objective: Use the rules of Algebra to isolate y.
[tex]4x - 2y = 18[/tex]
[tex] - 2y = 18 - 4x[/tex]
[tex]y = \frac{18 - 4x}{ - 2} [/tex]
[tex]y = - 9 + 2x[/tex]
Mr. Clinton went to the lumber company. He bought 6 boards at a cost of $4.12 per board and 5 pounds of nails at $0.78 per pound. What was the total cost for these items (not including tax)?
Answer:
djjdjdjdjdjdjdjdjdidi
$28.62 not including tax.
Twice the difference of a number and 6
Answer:
2x=6. I think friend it is correct.
Answer:
2(×-6)
Step-by-step explanation:
Correct me if im wrong thanks ●~●
Solve the given system by the substitution method.
3x + y = 8
7x - 4y = 6
Answer:
[tex]{ \tt{y = 8 - 3x}} - - - (i) \\ \\ = > 7x - 4(8 - 3x) = 6 \\ 7x - 32 + 12x = 6 \\ 19x - 32 = 6 \\ 19x = 38 \\ x = 2 \\ \\ = > y = 8 - 3(2) \\ y = 2[/tex]
The diameter of one circle is represented by 12x. The diameter of another circle is represented by 6x2y what is the ratio of the radiu of the two circles. 2:x3y 2x:y x:2y 2:xy
9514 1404 393
Answer:
(d) 2 : xy
Step-by-step explanation:
A common factor of 6x can be removed from the elements of the ratio. The ratio of radii is the same as the ratio of diameters.
12x : 6x²y = (6x)(2) : (6x)(xy) = 2 : xy
Answer:D
Step-by-step explanation:
5
12
of the pupils in Year 9 say their favourite colour is red.
There are 240 pupils in Year 9.
How many students said red is their favourite colour?
Answer:
100
Step-by-step explanation:
I assume you mean [tex]\frac{5}{12}[/tex] of the students in Year 9.
Basically, first you need to work out 1/12 of the students, which is just 240 divided by 12, equals 20.
So, we know 1/12 of 240 is 20, therefore, in order to work out 5/12, we must do 20 x 5, which is 100.
June, Gavyn and Alex share some sweets in the ratio 5:5:3. June gets 22 more sweets than Alex. How many sweets are there altogether?
Answer:
Let June's sweets be 5x.
Then Gavyn's sweets will be 5x.
And Alex's sweets will be 3x.
5x = 3x + 22
2x = 22
x = 11
So June has 5 x 11 = 55 sweets
Gavyn has 5 x 11 = 55 sweets
And Alex have 3 x 11 = 33 sweets
Total
= 55 + 55 + 33
= 143 sweets
Please help Ladder question!!
A 6 ft ladder, resting against a wall, begins to slip down the wall. When the angle of the ladder is 45 degrees, the bottom of the ladder is moving away from the wall at 0.5 m/s. At that moment, how fast is the top of ladder moving down the wall?
Answer:
Step-by-step explanation:
This is a related rates problem from calculus using implicit differentiation. The main equation is going to be Pythagorean's Theorem and then the derivative of that. Pythagorean's Theorem is
[tex]x^2+y^2=c^2[/tex] where c is the hypotenuse and is a constant. Therefore, the derivative of this with respect to time, and using implicit differentiation is
[tex]2x\frac{dx}{dt}+2y\frac{dy}{dt}=0[/tex] and dividing everything by 2 to simplify a bit:
[tex]x\frac{dx}{dt}+y\frac{dy}{dt}=0[/tex]. Upon analyzing that equation, it looks like we need values for x, y, [tex]\frac{dx}{dt}[/tex], and [tex]\frac{dy}{dt}[/tex]. And here's what we were given:
[tex]\theta=45[/tex] and [tex]\frac{dx}{dt}=.5[/tex] In the greater realm of things, that's nothing at all.
BUT we can use the right triangle and the angle we were given to find both x and y. The problem we are looking to solve is to
Find [tex]\frac{dy}{dt}[/tex] at the instant that [tex]\frac{dx}{dt}[/tex] = .5.
Solving for x and y:
[tex]tan45=\frac{x}{6}[/tex] and
6tan45 = x ( and since this is a 45-45-90 triangle, y = x):
[tex]6(\frac{\sqrt{2} }{2})=x=y[/tex] so
[tex]x=y=3\sqrt{2}[/tex] and now we can fill in our derivative. Remember the derivative was found to be
[tex]x\frac{dx}{dt}+y\frac{dy}{dt}=0[/tex] so
[tex]3\sqrt{2}(\frac{1}{2})+3\sqrt{2}\frac{dy}{dt}=0[/tex] and
[tex]\frac{3\sqrt{2} }{2}+3\sqrt{2} \frac{dy}{dt}=0[/tex] and
[tex]3\sqrt{2}\frac{dy}{dt}=-\frac{3\sqrt{2} }{2}[/tex] and multiplying by the reciprocal of the left gives us:
[tex]\frac{dy}{dt}=-\frac{3\sqrt{2} }{2}(\frac{1}{3\sqrt{2} })[/tex] so
[tex]\frac{dy}{dt}=-\frac{1}{2}\frac{m}{s}[/tex]
How high up the wall can a 12-foot ladder reach if its base is 4 feet from the wall? Round your answer to the nearest tenth of a foot if necessary.
Answer: 24 ft I think
Step-by-step explanation:
Can someone please help me with this math problem.
Answer:
8 + 30 ÷ 2 + 4 = 27
8 + 30 ÷ (2 + 4 ) = 13
(8 + 30) ÷ 2 + 4 = 23
Step-by-step explanation:
How many boxes could you stack safely on a pallet if the pallet is 5 feet deep, five feet across, every box is 1 x 1 and the maximum safe stacking height is 5 boxes? *
Answer:
125 boxes
Step-by-step explanation:
5*5*5
Create your own proportion problems?
Answer:
See Explanation
Step-by-step explanation:
Required
Proportion problems
An example is:
y is directly proportional to x such that: y=4 when x = 2;
Derive the equation
For direct proportions, we have:
[tex]y\ \alpha\ x[/tex]
This gives:
[tex]y = kx[/tex]
Make k the subject
[tex]k = y/x[/tex]
So:
[tex]k = 4/2 =2[/tex]
So, the equation is:
[tex]y = kx[/tex]
[tex]y = 2x[/tex]
Assume the above question is for inverse proportion
The variation will be:
[tex]y\ \alpha\ \frac{1}{x}[/tex]
This gives:
[tex]y\ = \frac{k}{x}[/tex]
Make k the subject
[tex]k =x*y[/tex]
[tex]k =2* 4 = 8[/tex]
So, the equation is:
[tex]y\ = \frac{k}{x}[/tex]
[tex]y = \frac{8}{x}[/tex]
Find the range of the data set represented by this box plot.
25
70
20
60
Answer:
D. 60
Step-by-step explanation:
Range is the difference between the maximum value and the minimum value.
The minimum value is at the extreme end of the whisker of the box plot to your left = 65
The maximum value is at the extreme end of the whisker of the box plot to your right = 125
Range = 125 - 65 = 60
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. At what rate is the volume of the cone changing when the radius is 140 in. and the height is 186 in.
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.
Cuál es el valor de x en la ecuación −7x+16=3x−4?
A.
2
Answer:
x=2
Step-by-step explanation:
16+4=3x+7x
20=10x
20/10=10x/10
2=x
what term can you add to
[tex] \frac{5}{6} x - 4[/tex]
to make it equivalent to
[tex] \frac{1}{2} x - 4[/tex]
9514 1404 393
Answer:
-1/3x
Step-by-step explanation:
We want to find the term 'a' such that ...
(5/6x -4) + a = (1/2x -4)
Add 4-1/2x to both sides.
(5/6 -1/2)x -4 +4 +a = 0
(5/6 -3/6)x + a = 0 . . . . . . express the fractions using a common denominator
1/3x + a = 0 . . . . . . . . . . simplify the difference
a = -1/3x . . . . . . . . . . .subtract 1/3x
The term you can add to make the desired equivalent is -1/3x.
X and Y are independent random variables. X has mean 100 and standard deviation 12. Y has mean 30 and standard deviation 9. What are the mean and standard deviation of (X–Y)?
Answer:
x is down and up and y is up then down
Step-by-step explanation:
I think
Question 8 of 9
Use a calculator to find the correlation coefficient of the data set.
х
у
2
15
6
13
7.
9
8
on 0
12 5
O A. -0.909
OB. 0.909
Ο Ο Ο
O C. 0.953
D. -0.953
Actual data table :
X __ y
2 15
6 13
7 9
8 8
12 5
Answer:
0.953
Step-by-step explanation:
The question isnt well formatted :
The actual data:
X __ y
2 15
6 13
7 9
8 8
12 5
Using a correlation Coefficient calculator, the correlation Coefficient obtained by fitting the data is 0.953 which depicts a strong linear correlation between the x and y variable. This shows that the value of y increases with a corresponding increase in x values and vice versa.
The sum of two numbers is 125. Their difference is 47. The two numbers are:
a)39 and 86.
b)40 and 85.
c)47 and 78.
d)None of these choices are correct.
Answer:
let x represent the bigger number
x+x-47=125
2x-47=125
2x=125+47
2x=172
2x/2=172/2
x=86
the smaller number=x-47
86-47
39
therefore the answer is a) 39 and 86
Answer:
A
Step-by-step explanation:
To find the sum of 125, you have to add the numbers.
39+86 = 125
To find the difference of 47, you have to subtract the numbers.
86-39 = 47
please help with this quadratic equations
Answer:
I don't understand the question
The radius of a sphere is increasing at a rate of 2 mm/s. How fast is the volume increasing (in mm3/s) when the diameter is 60 mm?
Answer:
22608 mm³/s
Step-by-step explanation:
Applying chain rule,
dV/dt = (dV/dr)(dr/dt)............... Equation 1
Where dV/dr = rate at which the volume is increasing
But,
V = 4πr³/3
Therefore,
dV/dr = 4πr²............... Equation 2
Substitute equation 2 into equation 1
dV/dt = 4πr²(dr/dt).............. Equation 3
From the question,
Given: dr/dt = 2 mm/s, r = 60/2 = 30 mm
Consatant: π = 3.14
Substitute these values into equation 3
dV/dt = 4×3.14×30²×2
dV/dt = 22608 mm³/s