the cost of 7 shirts is $63. find the cost of 5 shirts
1. $35
2. $45
3. $52
4. $70
I want to find the inverse for the following function, but I think there is a mistake. Identify the first mistake in the following process. Explain how to fix the mistake.
Answer:
Step-by-step explanation:
The only mistake is in the last line. You need to replace the y by x, So:
f-1(x) = (x - 4)/-8
It's usual to put the negative on the top so it becomes
-(x -4)/8
- and we can simplify this a bit more to give
f-1(x) = (4 - x)/5
1 point
What is the slope of a line perpendicular to 3x + 4y = -2?
Answer:
4/3
Step-by-step explanation:
In slope-intercept form [tex]y=mx+b[/tex], [tex]m[/tex] represents the slope of the line.
Let's write [tex]3x+4y=-2[/tex] in slope-intercept form by isolating [tex]y[/tex]:
[tex]3x+4y=-2,\\4y=-3x-2,\\y=-\frac{3}{4}x-\frac{1}{2}[/tex]
Therefore, the slope of this line is [tex]\frac{-3}{4}[/tex]. To find the slope of a line perpendicular to it, multiply the reciprocal of the slope by -1 (take the negative reciprocal).
Therefore, the slope of a line perpendicular to [tex]3x+4y=-2[/tex] is:
[tex]m_{perp}=-(-\frac{4}{3})=\boxed{\frac{4}{3}}[/tex]
Answer:
4/3
Given equation :-
3x + 4y = -2 4y = -3x - 2 y = (-3x - 2)/4 y = -3/4 x - 1/2Slope :-
m = -3/4Slope of perpendicular line :-
m' = -(1/m )m' = -( 1 ÷ -3/4 ) m' = -1 * -4/3 m = 4/3A certain financial services company uses surveys of adults age 18 and older to determine if personal financial fitness is changing over time. A recent sample of 1,000 adults showed 410 indicating that their financial security was more than fair. Suppose that just a year before, a sample of 1,200 adults showed 420 indicating that their financial security was more than fair.
Required:
a. State the hypotheses that can be used to test for a significant difference between the population proportions for the two years.
b. Conduct the hypothesis test and compute the p-value. At a 0.05 level of significance, what is your conclusion?
c. What is the 95% confidence interval estimate of the difference between the two population proportions?
d. What is your conclusion?
Answer:
b) Then z(s) is in the rejection region for H₀. We reject H₀. The p-value is smaller than α/2
c)CI 95 % = ( 0.00002 ; 0.09998)
Step-by-step explanation: In both cases, the size of the samples are big enough to make use of the approximation of normality of the difference of the proportions.
Recent Sample
Sample size n₁ = 1000
Number of events of people with financial fitness more than fair
x₁ = 410
p₁ = 410/ 1000 = 0.4 then q₁ = 1 - p₁ q₁ = 1 - 0.4 q₁ = 0.6
Sample a year ago
Sample size n₂ = 1200
Number of events of people with financial fitness more than fair
x₂ = 420
p₂ = 420/1200 p₂ = 0.35 q₂ = 1 - p₂ q₂ = 1 - 0.35 q₂ = 0.65
Test Hypothesis
Null Hypothesis H₀ p₁ = p₂
Alternative Hypothesis Hₐ p₁ ≠ p₂
CI 95 % then significance level α = 5% α = 0.05 α/2 = 0.025
To calculate p-value:
SE = √ (p₁*q₁)/n₁ + (p₂*q₂)/n₂
SE = √ 0.4*0.6/1000 + 0.65*0.35/1200
SE = √ 0.00024 + 0.000189
SE = 0.021
z(s) = ( p₁ - p₂ ) / SE
z(s) = ( 0.4 - 0.35 )/0.021
z(s) = 0.05/ 0.021
z(s) = 2.38
We find p-value from z-table to be p-value = 0.00842
Comparing
p-value with α/2 = 0.025
α/2 > p-value
Then z(s) is in the rejection region for H₀. We reject H₀
CI 95 % = ( p₁ - p₂ ) ± 2.38*SE
CI 95 % = ( 0.05 ± 2.38*0.021 )
CI 95 % = ( 0.05 ± 0.04998)
CI 95 % = ( 0.00002 ; 0.09998)
CI 95 % does not contain the 0 value affirming what the hypothesis Test already demonstrate
find the exact value cos5pi/6
Answer:
[tex] - \frac{ \sqrt{3} }{2} [/tex]
Step-by-step explanation:
Unit circle
What is the solution to the system of linear equations?
(-3,0)
(-3,3)
(0,2)
(3,1)
PLEASE ANYONE definition of a percent increase?
Answer:
In any quantitative science, the terms relative change and relative difference are used to compare two quantities while taking into account the "sizes" of the things being compared. The comparison is expressed as a ratio and is a unitless number.
Step-by-step explanation:
I hope it helps
DO THIS AND ILL MARK! PLEASE
Answer:
Sin = 7/25
Cos = 24/25
Tan = 7/24
Step-by-step explanation:
The ratio for sin is opposite/hypotenuse, cos is adjacent/ hypotenuse, and tan is opposite/ adjacent.
Simplify this algebraic expression.
y-3/3 +12
O A. y-11
O B. y + 13
O c. y-5
O D. y+ 11
Answer:
D
Step-by-step explanation:
[tex]y - \frac{3}{3} + 12[/tex]
[tex]y - 1 + 12[/tex]
[tex]y + 11[/tex]
A home gardener estimates that 24 apple trees will have an average yield of 104 apples per tree. But because of the size of the garden, for each additional tree planted the yield will decrease by two apples per tree. (a) How many additional trees should be planted to maximize the total yield of apples
Answer:
The farmer should plant 14 additional trees, for maximum yield.
Step-by-step explanation:
Given
[tex]Trees = 24[/tex]
[tex]Yield = 104[/tex]
[tex]x \to additional\ trees[/tex]
So, we have:
[tex]Trees = 24 + x[/tex]
[tex]Yield = 104 - 2x[/tex]
Required
The additional trees to be planted for maximum yield
The function is:
[tex]f(x) = Trees * Yield[/tex]
[tex]f(x) = (24 + x) * (104 - 2x)[/tex]
Open bracket
[tex]f(x) = 24 * 104 + 104x - 24 * 2x - x * 2x[/tex]
[tex]f(x) = 2796 + 104x - 48x - 2x^2[/tex]
[tex]f(x) = 2796 + 56x - 2x^2[/tex]
Rewrite as:
[tex]f(x) = - 2x^2 + 56x + 2796[/tex]
Differentiate
[tex]f'(x) = -4x + 56[/tex]
Equate [tex]f'(x) = -4x + 56[/tex] to 0 and solve for x to get the maximum of x
[tex]-4x + 56 = 0[/tex]
[tex]-4x =- 56[/tex]
Divide by -4
[tex]x =14[/tex]
The farmer should plant 14 additional trees, for maximum yield.
What is the Value of the expression 1/4(c cubed + d squared) when c = -4 and d = 10
Answer: 9
Step-by-step explanation:
[tex]\frac{1}{4} (c^{3}+d^{2})[/tex]
c = -4d = 10Substitute in the values into the expression:
[tex]\frac{1}{4} ((-4)^{3}+10^{2})\\\\=\frac{1}{4}(-64+100)\\\\=\frac{1}{4}(36)\\\\=\frac{36}{4} =9[/tex]
What are the coordinates of the point shown on the coordinate plane?
Answer:
(5,4)
Step-by-step explanation:
The coordinates of a point are the x and y-values of a point. It is organized like (x,y). The x-value is written first and then the y-value. The x-value is the "run" or the horizontal value; so, the value of the axis on the bottom. The y-value is the "rise" or the vertical value. The axes are also labeled. For this graph, the x-value is 5 and the y-value is 4. The final answer is (5,4).
The diameters of ball bearings are distributed normally. The mean diameter is 87 millimeters and the standard deviation is 6 millimeters. Find the probability that the diameter of a selected bearing is greater than 84 millimeters. Round your answer to four decimal places.
Answer:
69.14% probability that the diameter of a selected bearing is greater than 84 millimeters
Step-by-step explanation:
According to the Question,
Given That, The diameters of ball bearings are distributed normally. The mean diameter is 87 millimeters and the standard deviation is 6 millimeters. Find the probability that the diameter of a selected bearing is greater than 84 millimeters.
In a set with mean and standard deviation, the Z score of a measure X is given by Z = (X-μ)/σwe have μ=87 , σ=6 & X=84
Find the probability that the diameter of a selected bearing is greater than 84 millimetersThis is 1 subtracted by the p-value of Z when X = 84.
So, Z = (84-87)/6
Z = -3/6
Z = -0.5 has a p-value of 0.30854.
⇒1 - 0.30854 = 0.69146
0.69146 = 69.14% probability that the diameter of a selected bearing is greater than 84 millimeters.Note- (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)
Write the formula of the function y whose graph is shown.
Answer:
This looks like the graph of [tex]f(x)=\frac{1}{x}[/tex] ! That's a reciprocal graph.
45 is what percent of 78?
Answer:
35.1
Step-by-step explanation:
45×78/100 that's 100% correct
What equation can I use to pick numbers 1-70 if they're picked randomly
9514 1404 393
Answer:
you cannot use an equation to pick random numbers
Step-by-step explanation:
"Picked randomly" and "using an equation" are mutually exclusive. A random number cannot be predicted, so an equation cannot be used to generate it.
That being said, many programming languages make use of a "linear congruential generator" for generating random numbers. Such a generator generates a next number (x') from a previous number (x) using the equation ...
x' = (a·x +c) mod m
Numbers generated in this way are called "pseudo-random numbers." The sequence of generated numbers will repeat at some point, and the statistics of generated numbers may or may not be suitable for any given application. (For example, sequential numbers may tend to be correlated.) The distribution of numbers is inherently uniform, so if you need other distribution, you need to perform some math on what you get from a linear congruential generator. Methods are available for approximating about any kind of distribution you might want.
This is not the only "equation" that can be used, and is certainly not the best.
__
A variety of different values of a, c, m are used in generators of this type. Some are better than others at producing what looks like randomness. Here's a set of numbers you can try: (no claim is made regarding suitability for your purpose)
a = 1140671485c = 12820163m = 2^24 = 16777216This will produce numbers in the range 0–16777215. To get numbers in the range of 1-70, you can map these to your range in any suitable fashion. For example, you could add 1 to the integer part of the result from division by 239675.
Below is a graph of the sorted output of 200 values in the range 1–70 from the generator described here. You can see the distribution is approximately linear, and that some values are missing while others show up more often than average. (You expect this with random numbers.) The seed for these numbers (first value of x) is 1337457.
__
There is a web site available that will produce random numbers to your specification, based on the background noise of the universe. They are truly random.
A telephone exchange operator assumes that 9% of the phone calls are wrong numbers. If the operator is correct, what is the probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%
Answer:
0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more 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 telephone exchange operator assumes that 9% of the phone calls are wrong numbers.
This means that [tex]p = 0.09[/tex]
Sample of 448
This means that [tex]n = 448[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.09[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{448}} = 0.0135[/tex]
What is the probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%?
More than 9% + 3% = 12 or less than 9% - 3% = 6%. Since the normal distribution is symmetric, these probabilities are the same, so we find one of them and multiply by 2.
Probability it is less than 6%
P-value of Z when X = 0.06. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.06 - 0.09}{0.0135}[/tex]
[tex]Z = -2.22[/tex]
[tex]Z = -2.22[/tex] has a p-value of 0.0132
2*0.0132 = 0.0264
0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%
The domain of the function f(x)=-x3+4
Answer:
Domain= {x:x £|R}
|R=any real number
NO LINKS OR ANSWERING WHAT YOU DON'T KNOW!!!
9. Suppose y varies inversely with x, and y = 49 when x = 1/7. What is the value of x when y = 7?
a. 14
b. 2
c. 1
d. 7
10. Suppose y varies inversely with x, and y = 5 when x = 3. What is the inverse variation equation that relates x and y?
a. y = 3/x
b. y = 5/x
c. y = 15/x
d. y = 15x
9514 1404 393
Answer:
9. c. 1
10. c. y = 15/x
Step-by-step explanation:
The equation for inverse variation can be written as ...
y = k/x
The value of k can be determined from given values of x and y. Multiply by x to get ...
k = xy
Solving for x, you get ...
x = k/y
___
9. k = (1/7)(49) = 7
x = k/y = 7/7
x = 1
__
10. k = (3)(5) = 15
y = 15/x
How many ways are there to assign four jobs to 7 employees if no employee can be given more than one job
Answer:
35ways
Step-by-step explanation:
Given the following
Total employees = 7employees
Number of tasks to be assigned = 4task
The number of ways this can be done is expressed as 7C4
7C4 = 7!/(7-4)!4!
7C4 = 7!/3!4!
7C4 = 7*6*5*4!/6*4!
7C4 = 35ways
Hence this can be done in 35ways
What is the value of x?
Answer:
Step-by-step explanation:
the ratio of 24 to 36 is the same as x to 12
[tex]\frac{24}{36}[/tex] = [tex]\frac{x}{12}[/tex]
then
12*([tex]\frac{24}{36}[/tex])=x
[tex]\frac{24}{3}[/tex] = x
8 = x
that's it :)
help e please i’ll give brainliest
Answer:
363,000,000
..........
If the domain of a function that is rotated 90 degrees counter-clockwise is (0, 0), (3, 5), (-1, 4), what is the range?
A. (0, 0), (5, 3), (4, -1)
B. (0, 0), (5, -3), (4, 1)
C. (0, 0), (-3, -5), (1, -4)
D. (0, 0), (-5, 3), (-4, -1)
Answer:
the answer is B. (0,0) (5,-3) (4,1)
please mark me brainlist
Step-by-step explanation:
Answer:
Your answer is
Step-by-step explanation:
Your answer is B.(0, 0), (5, -3), (4, 1)
William has been contracted to paint a school classroom. The classroom is 20 m long, 15 m wide and 5 m high. There are four windows (2m by 3m) and a door (2m by 1m). Determine the cost of painting the ceiling at N$ 6.50/m²
Answer:
Step-by-step explanation:
l -> length
b -> width
h -> height
Find the area of four walls and ceiling. then subtract the area of four windows and a door form that area.
Area of four walls + ceiling = 2( lh + bh) +lb
= 2*(20*5 + 15*5) + 20*15
= 2( 100 + 75) + 300
= 2* 175 + 300
= 350 +300
= 650 sq m
Area of window = 2 *3 = 6 sq.m
Area of four windows = 4*6 = 24 sq.m
Area of door = 2 * 1 = 2 sq.m
Area of four walls excluding 4 windows and door = 650 - 24 - 2 = 624 sq.m
Cost of painting = 624 * 6.50
= $ 4056
Answer: 1950 dollars to paint the ceiling only (ignoring the walls)
The cost to paint the walls only is 2106 dollars.
The cost to paint the walls and ceiling is 4056 dollars.
==================================================
Explanation:
It seems a bit strange how your teacher mentions the windows and doors, but then asks about the ceiling only. Perhaps this is a red herring, but I'm not sure.
Anyway, to directly answer the question, we'll need to find the area of the ceiling first. The ceiling is a rectangle of dimensions 20 m by 15 m, so its area is 20*15 = 300 square meters.
Since paint costs 6.50 dollars per square meter, the total cost for the ceiling alone is 6.50*300 = 1950 dollars
If your teacher only cares about the ceiling, then you can stop here (and ignore the next section below).
---------------------------
If you wanted to find the cost to paint the walls, then we need to find the area of the walls.
For now, ignore the windows and door. Two opposite walls have area of 20*5 = 100 m^2 each. That accounts for 2*100 = 200 m^2 of wall area so far.
The other pair of opposite walls have area 15*5 = 75 m^2 each. That's another 2*75 = 150 m^2 of wall area.
In all, the total wall area without considering the windows or door is 200+150 = 350 m^2.
Now we consider the windows. Each window is 2 m by 3 m, yielding an area of 2*3 = 6 m^2. Four such windows have a total area of 4*6 = 24 m^2.
The door is 2 m by 1 m, so its area is 2*1 = 2 m^2
We'll subtract the wall area and the combined window+door areas to get
wallArea - windowArea - doorArea = 350-24-2 = 324
So after accounting for the windows and door, the amount of wall to paint is 324 m^2, which leads to a cost of 6.50*324 = 2106 dollars.
Therefore, painting the walls and ceiling gets us a total cost of 1950+2106 = 4056 dollars
This section is entirely optional if your teacher only cares about the ceiling.
Choose all that apply:
1.Circle A and circle A', have the same circumference.
2.The radii of circle A and circle A', have the same lengths.
3. Points A and A', are both on the xxx-axis.
4. None of the above
Answer:
Step-by-step explanation:
1. Circle A and circle A', have the same circumference. (Yes)
2. The radii of circle A and circle A', have the same lengths. (Yes)
3. .... (No)
4. ... (No)
What is the following product? Assume x>0 and y>0 v5x^8y^2•v10^3•v12y
Answer:
[tex]10x^{5}y \sqrt{6xy}[/tex]
Step-by-step explanation:
Find the values of x and y that make these triangles congruent by the HL theorem
Answer:
x = 3, y = 2Step-by-step explanation:
As due to congruency,
x + 3 = 3y
[By putting the values of x = 3 and y = 2]
=> 3 + 3 = 3 × 2
=> 6 = 6
and,
x = y + 1
[By putting the values of x = 3 and y = 2]
=> 3 = 2 + 1
=> 3 = 3
Hence, proved
A 17 feet ladder is placed against a building. The bottom of the ladder is 15 feet away from the building. How many feet high is the top of the ladder?
7 feet
12 feet
8 feet
15 feet
Answer:
[tex]8 \ feet[/tex]
Step-by-step explanation:
In this situation, one is given the following information. A ladder is leaning against a wall and has a measure of (17) feet. The bottom of the ladder is (15) feet away from the wall. One can infer that the wall forms a right angle with the ground. Thus, the triangle formed between the ground, ladder, and wall is a right triangle. Therefore, one can use the Pythagorean theorem. The Pythagorean theorem states the following,
[tex]a^2+b^2=c^2[/tex]
Where (a) and (b) are the legs or the sides adjacent to the right angle of the right triangle. The parameter (c) represents the hypotenuse or the side opposite the right angle. In this case, the legs are the ground and wall, and the hypotenuse is the ladder. Substitute this into the formula a solve for the height of the wall.
[tex]a^2+b^2=c^2[/tex]
Substitute,
[tex](ground)^2+(wall)^2=(ladder)^2\\\\(15)^2+(wall)^2=(17)^2\\[/tex]
Simplify,
[tex](15)^2+(wall)^2=(17)^2\\\\225+(wall)^2=289[/tex]
Inverse operations,
[tex]225+(wall)^2=289\\\\(wall)^2=64\\\\wall=8[/tex]
Exactly how many planes contain points J, K, and N?
a - 0
b - 1
c - 2
d - 3
For a popular Broadway music the theater box office sold 356 tickets at $80 a piece275 tickets at $60 a piece and 369 tickets at $ 45 a piece. How much money did the box office take in?
Answer:
Step-by-step explanation:
356 * 80 = 28 480
275 * 60 = 16 500
369 * 45 = 16 605
sum = $ 61 585