Answer:
-7x-11
Step-by-step explanation:
expand brackets
6-3x-10+8-4x=15
4-7x=15
move 15 to left side
-7x-11
Answer:
4-7x=15
Step-by-step explanation:
[tex]6 - (3x + 10) + 4(2 - x) = 15 \\ 6- 3x - 10 + 8 - 4x = 15 \\ - 7x = 15 + 10 - 8 - 6\\ - 7x = 11 \\ the \: same \: one \: is \\ 4 - 7x = 15[/tex]
Exercise 6.2
1.
a.
The total cost function is given by C = 100 - 5x + 7x2, find
the average cost and marginal cost.
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Answer:
average cost = 7x -5 +100/xmarginal cost = 14x -5Step-by-step explanation:
The average cost is the total cost divided by the number of units produced:
average cost = C/x = 100/x -5 +7x
__
The marginal cost is the derivative of the total cost function.
marginal cost = -5 +14x
if qqq=90 what's qqqq+87
Answer: [tex]90\sqrt[3]{90}+87[/tex]
Step-by-step explanation:
[tex]qqq=90\\q^3=90\\\sqrt[3]{q^3} =\sqrt[3]{90}\\q= \sqrt[3]{90}\\\\qqqq+87\\q^3q^1+87\\90\sqrt[3]{90}+87[/tex]
A bank wishes to estimate the mean balances owed by customers holding Mastercard. The population standard deviation is estimated to be $300. If a 98% confidence interval is used and the maximum allowable error is $80, how many cardholders should be sampled?
A. 76
B. 85
C. 86
D. 77
Answer:
D. 77
Step-by-step explanation:
We have 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 p-value 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.
The population standard deviation is estimated to be $300
This means that [tex]\sigma = 300[/tex]
If a 98% confidence interval is used and the maximum allowable error is $80, how many cardholders should be sampled?
This is n for which M = 80. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]80 = 2.327\frac{300}{\sqrt{n}}[/tex]
[tex]80\sqrt{n} = 2.327*300[/tex]
[tex]\sqrt{n} = \frac{2.327*300}{80}[/tex]
[tex](\sqrt{n})^2 = (\frac{2.327*300}{80})^2[/tex]
[tex]n = 76.15[/tex]
Rounding up:
77 cardholders should be sampled, and the correct answer is given by option d.
Bill wants to attend a college with a current tuition of $10,000 a year. He will graduate from high school in five years. Roughly how much will Bill need to save for one-year’s tuition to account for an annual rate of inflation of 3%?
A. $638.30
B. $667.50
C. $656.50
D. $633.30
Answer:
I think the anser is 667.50
Step-by-step explanation:
Use the confidence level and sample data to find a confidence interval for estimating the population μ. Round your answer to the same number of decimal places as the sample mean.
Test scores: n = 92, = 90.6, σ = 8.9; 99% confidence
Options:
A.) 88.2 < μ < 93.0
B.) 88.4 < μ < 92.8
C.) 89.1 < μ < 92.1
D.) 88.8 < μ < 92.4
Answer: Choice A.) 88.2 < μ < 93.0
=============================================================
Explanation:
We have this given info:
n = 92 = sample sizexbar = 90.6 = sample meansigma = 8.9 = population standard deviationC = 99% = confidence levelBecause n > 30 and because we know sigma, this allows us to use the Z distribution (aka standard normal distribution).
At 99% confidence, the z critical value is roughly z = 2.576; use a reference sheet, table, or calculator to determine this.
The lower bound of the confidence interval (L) is roughly
L = xbar - z*sigma/sqrt(n)
L = 90.6 - 2.576*8.9/sqrt(92)
L = 88.209757568781
L = 88.2
The upper bound (U) of this confidence interval is roughly
U = xbar + z*sigma/sqrt(n)
U = 90.6 + 2.576*8.9/sqrt(92)
U = 92.990242431219
U = 93.0
Therefore, the confidence interval in the format (L, U) is approximately (88.2, 93.0)
When converted to L < μ < U format, then we get approximately 88.2 < μ < 93.0 which shows that the final answer is choice A.
We're 99% confident that the population mean mu is somewhere between 88.2 and 93.0
As...
Which of the following geometric series diverges?
Answer:
II and II only.
Step-by-step explanation:
The first series converges because the common ratio r is 0.8 (<1).
II diverges as |r| > 1.
III is an alternating series with r = -4 - that is |r| = 4 so it diverges.
From the given-series, the series which diverges are : (ii) 4 + 8 + 16 + 32; and (iii) 2 - 8 + 32 - 128 + ..., So, correct option is (a) (ii) and (iii) only.
In option (ii), the series 4 + 8 + 16 + 32 is a geometric series with a common ratio of 2. We see that the "common-ratio" is greater than 1, this series diverges.
In option (iii), the series 2 - 8 + 32 - 128 is a geometric series with a common-ratio of |-4| = 4. We see that the "absolute-value" of the "common-ratio" is greater than 1, this series also diverges.
But, in option (i), the series -9.2 - 7.36 - 5.888 - 4.7104 is a geometric series with a common ratio of |-0.8| = 0.8. Since the "absolute-value" of the "common-ratio" is less than 1, this series converges.
Therefore, the correct answer is (a) (ii) and (iii) only.
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Find the arc length of the 3/4 of a circle with a radius of 5
Answer:
7.5 pi
Step-by-step explanation:
The formula for arc length of a sector is denoted as
[tex]\frac{x}{360}2\pi r[/tex], where x is the central angle of the sector.
Since the sector is 3/4 of a circle, the central angle will be 3/4 of 360 degrees.
3/4 of 360 is 270, so we have our central angle. We also have our radius which we can plug into the formula.
[tex]\frac{270}{360}2(5)\pi[/tex]
2 times 5 is equal to 10, and 270/360 simplifies to 3/4. 3/4 times 10 is equal to 7.5, so the answer is 7.5 pi
To study the mean respiratory rate of all people in his state, Frank samples the population by dividing the residents by towns and randomly selecting 12 of the towns. He then collects data from all the residents in the selected towns. Which type of sampling is used
Answer:
Cluster Sampling
Step-by-step explanation:
Cluster Sampling involves the random sampling of observation or subjects, which are subsets of a population. Cluster analysis involves the initial division of population subjects into a number of groups called clusters . From the divided groups or clusters , a number of groups is then selected and it's elements sampled randomly. In the scenario above, the divison of the population into towns where each town is a cluster. Then, the selected clusters (12) which are randomly chosen are analysed.
USE THE PRESENT VALUE FORMULA TO CALCULATE THE AMOUNT OF MONEY THAT MUST BE INVESTED NOW AT 9% ANNUALLY COMPOUNDED QUARTERLY TO OBTAIN 1,000 IN 4 YEARS.
Answer:
The amount of money that must be invested is $252.
Step-by-step explanation:
Present value formula:
The present value formula is given by:
[tex]P = \frac{F}{(1+r)^n}[/tex]
In which:
P is the present value.
F is the future value.
r is the interest rate.
n is the number of periods.
9% ANNUALLY
This means that [tex]r = 0.09[/tex]
COMPOUNDED QUARTERLY TO OBTAIN 1,000 IN 4 YEARS.
Obtain 1000 means that [tex]F = 1000[/tex]
Compounded quarterly in 4 years, so 4*4 = 16 periods and [tex]n = 16[/tex].
Amount of money that must be invested:
[tex]P = \frac{F}{(1+r)^n}[/tex]
[tex]P = \frac{1000}{(1+0.09)^{16}}[/tex]
[tex]P = 252[/tex]
The amount of money that must be invested is $252.
5/10+4/16 in simplest form
If a system including the quadratic equation representing the parabola and a linear equation has no solution, which linear equation could be the second equation in the system? A. 1/2x=y+4 B. 2x-y=0 C.y=6 D.y=2x+6
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Answer:
D. y=2x+6
Step-by-step explanation:
The line cannot intersect the parabola if it has a y-intercept greater than 5 and a suitable slope. The only sensible answer choice is ...
y = 2x +6
Answer:
D. y = 2x + 6.
Step-by-step explanation:
The required equation would not intersect the parabola at any point.
The only one to fit that is D.
The smallest whole number is _______.
Step-by-step explanation:
The smallest whole number is 0 .A rectangular floor is 9 yards long and 3 yards wide. What is the area
Instructions: Find the missing side. Round your answer to the nearest tenth.
22
58°
Answer:
x = 19.2
Step-by-step explanation:
tan(58)=x/12
x=12×tan(58)
x=19.2
Answered by GAUTHMATH
State if the scenario involves a permutation or a combination. Then find the number of possibilities.
The student body of 290 students wants to elect a president and vice president.
Permutation/Combination:
Answer:
Answer:
Permutation. ; 83810 ways
Step-by-step explanation:
Permutation and combination methods refers to mathematical solution to finding the number of ways of making selection for a group of objects.
Usually, selection process whereby the order of selection does not matter are being treated using permutation, while those which takes the order of selection into cognizance are calculated using combination.
Here, selecting 2 members (president and vice president) from 290 ; since order of arrangement does not matter, we use permutation ;
Recall :
nPr = n! ÷ (n - r)!
Hence,
290P2 = 290! ÷ (290 - 2)!
290P2 = 290! ÷ 288!
290P2 = (290 * 289) = 83810 ways
please can anyone help me with this question what is the probability of the spinner landing on an even number.
ive gotten it wrong like 4 times n i cannot figure it out pls help
Answer:
x = 74.74 m
Step-by-step explanation:
you need simple trigonometry to solve it
cosine of an angle is the ratio of the adjacent side to the hypotenuse
cos(42.2) is about 0.74
so X / Hypotenuse = 0.74
we know hypotenuse is 101 m
X / 101 = 0.74
x = 74.74 m
hope this helped!
The president of the student council wants to survey the student population about parking. She decides to take a random sample of 100 of the 1,020 students at the school. Which of the following correctly labels the population?
1–1020
01–1020
001–1020
0001–1020
I think its (B), 01-1020.
Answer:
Should be (B)
01-1020
ED2021
The correct label for the population is 1 - 1020,
Option A is the correct answer.
What is random sampling?It is the way of choosing a number of required items from a number of population given.
Each items has an equal probability of being chosen.
We have,
The population in this case refers to the entire group of interest, which is the entire student body of the school.
The total number of students is 1,020.
The population is usually labeled with a range or interval that includes all the possible values of the variable of interest.
In this case, the variable of interest is whether or not a student has an opinion on parking.
The correct label for the population is 1-1020, as this range includes all possible student identification numbers at the school.
The other options (01-1020, 001-1020, and 0001-1020) are not correct because they suggest that there are leading zeros in the student identification numbers, which is not usually the case.
Thus,
The correct label for the population is 1-1020,
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2. How many solutions does this system of equations have? *
y = 5x – 2
y = 5x + 7
Answer:
No solution.
Step-by-step explanation:
[tex]{ \sf{y = ±∞ \: \: and \: \: x = ±∞}}[/tex]
The SAT and ACT college entrance exams are taken by thousands of students each year. The scores on the exam for any one year produce a histogram that looks very much like a normal curve. Thus, we can say that the scores are approximately normally distributed. In recent years, the SAT mathematics scores have averaged around 480 with standard deviation of 100. The ACT mathematics scores have averaged around 18 with a standard deviation of 6.
a. An engineering school sets 550 as the minimum SAT math score for new students. What percent of students would score less than 550 in a typical year?
b. What would the engineering school set as comparable standard on the ACT math test?
c. What is the probability that a randomly selected student will score over 700 on the SAT math test?
Answer:
a) 75.8% of students would score less than 550 in a typical year.
b) The comparable standard would be a minimum ACT score of 22.2.
c) 0.0139 = 1.39% probability that a randomly selected student will score over 700 on the SAT math test.
Step-by-step explanation:
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.
Question a:
SAT, so mean of 480 and standard deviation of 100, that is, [tex]\mu = 480, \sigma = 100[/tex]
The proportion is the p-value of Z when X = 550. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{550 - 480}{100}[/tex]
[tex]Z = 0.7[/tex]
[tex]Z = 0.7[/tex] has a p-value of 0.758.
0.758*100% = 75.8%
75.8% of students would score less than 550 in a typical year.
b. What would the engineering school set as comparable standard on the ACT math test?
ACT, with a mean of 18 and a standard deviation of 6, so [tex]\mu = 18, \sigma = 6[/tex]
The comparable score is X when Z = 0.7. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.7 = \frac{X - 18}{6}[/tex]
[tex]X - 18 = 0.7*6[/tex]
[tex]X = 22.2[/tex]
The comparable standard would be a minimum ACT score of 22.2.
c. What is the probability that a randomly selected student will score over 700 on the SAT math test?
This is 1 subtracted by the p-value of Z when X = 700, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{700 - 480}{100}[/tex]
[tex]Z = 2.2[/tex]
[tex]Z = 2.2[/tex] has a p-value of 0.9861.
1 - 0.9861 = 0.0139
0.0139 = 1.39% probability that a randomly selected student will score over 700 on the SAT math test.
Rearrange to make P the subject, :)..
Answer: [tex]P = \frac{25}{E^2}-Q\\\\[/tex]
Work Shown:
[tex]E = 5\left(\sqrt{\frac{1}{P+Q}}\right)\\\\5\left(\sqrt{\frac{1}{P+Q}}\right) = E\\\\\sqrt{\frac{1}{P+Q}} = \frac{E}{5}\\\\\frac{1}{P+Q} = \left(\frac{E}{5}\right)^2\\\\\frac{1}{P+Q} = \frac{E^2}{25}\\\\P+Q = \frac{25}{E^2}\\\\P = \frac{25}{E^2}-Q\\\\[/tex]
Which of the following points would fall on the line produced by the point-slope form equation y - 10 = 3(x - 11) when graphed?
Answer:
(-5,-37)
(-4,-34)
(-3,-31)
(-2,-28)
(-1,-25)
(0,-22)
(1,-19)
(2,-16)
(3,-13)
(4,-10)
(5,-7)
(6,-4)
Step-by-step explanation:
y - 10 = 3(x - 11)
y - 10 = 3x - 33
y = 3x -22
plzzzzz helllllllppppppp worth 25 points
Answer:
Step-by-step explanation:
Let's fill that in with what the variables are "worth":
(3)(-3)+2(-2) and simplify to
-9 + (-4) which, when you add those 2 negatives, gives you
-13, choice B.
Answer:
[tex]x = 3 \\ y = - 3 \\ z = - 2 \\ xy + 2z = 3 \times - 3 + 2 \times - 2 \\ = - 9 - 4 \\ = - 13 \\ thank \: you[/tex]
Please use the accompanying Excel data set or accompanying Text file data set when completing the following exercise. A machine produces metal rods used in an automobile suspension system. A random sample of 15 rods is selected and the diameter is measured. The resulting data (in millimeters) are as follows: No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Dia. 8.23 8.16 8.23 8.25 8.26 8.23 8.20 8.26 8.19 8.23 8.20 8.28 8.24 8.25 8.24 Use the data above to calculate a 95% two-sided confidence interval on the mean rod diameter. Assume the data are normally distributed. (a) Calculate the sample mean and standard deviation. Round the sample mean and the sample standard deviation to 2 and 3 decimal places respectively (e.g. 98.76 and 98.765). (b) Calculate the 95% two-sided confidence interval on the true mean rod diameter. Round your answers to 3 decimal places (e.g. 98.765).
Answer:
(8.213 ; 8.247)
Step-by-step explanation:
Given the data :
No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Dia. 8.23 8.16 8.23 8.25 8.26 8.23 8.20 8.26 8.19 8.23 8.20 8.28 8.24 8.25 8.24
Sanple size, n = 15
Sample mean, xbar = Σx / n = 123.45 / 15 = 8.23
The sample standard deviation, s = √(x -xbar)²/n-1
Using calculator :
Sample standard deviation, s = 0.03116
s = 0.031 (3 decimal places)
The 95% confidence interval :
C.I = xbar ± (Tcritical * s/√n)
Tcritical at 95%, df = 15 - 1 = 14
Tcritical = 2.145
C.I = 8.23 ± (2.145 * 0.031/√15)
C.I = 8.23 ± 0.0171689
C.I = (8.213 ; 8.247)
Gina charges an initial fee and an hourly fee to babysit. Using the table below find the hourly fee and the initial fee that
Gina charges to babysit. Show work.
You randomly select one card from a 52-card deck. Find the probability of selecting the 9 of spades or the 3 of clubs.
The probabilitiy is ___.
(Type an integer or a fraction. Simplify your answer.)
Answer:
2/52=1/26
Step-by-step explanation:
A population proportion is 0.57. Suppose a random sample of 657 items is sampled randomly from this population.
a. What is the probability that the sample proportion is greater than 0.58?
b. What is the probability that the sample proportion is between 0.54 and 0.60?
c. What is the probability that the sample proportion is greater than 0.56?
d. What is the probability that the sample proportion is between 0.53 and 0.55?
e. What is the probability that the sample proportion is less than 0.48?
A store surveyed their customers to find out their ages. The bar graph below shows the number of customers in each age group. What percent of customers surveyed were over 50%? Round your answer to 1 decimal place.
Bar graphs are used to represent data, where the vertical axis represents the frequency and the horizontal axis.
The percentage that is over 50 is 15.6%:
The data on the bar graph can be represented as:
Under 17 [tex]\to[/tex] 25
18 - 24 [tex]\to[/tex] 35
25 - 34 [tex]\to[/tex] 40
35 - 50 [tex]\to[/tex] 35
Over 50 [tex]\to[/tex] 25
So, the total customer surveyed are:
[tex]Total = 25 + 35 + 40 + 35 + 25[/tex]
[tex]Total = 160[/tex]
The percentage over 50 are:
[tex]\%Over\ 50 = \frac{Over\ 50}{Total } * 100\%[/tex]
[tex]\%Over\ 50 = \frac{25}{160} * 100\%[/tex]
[tex]\%Over\ 50 = 0.15625* 100\%[/tex]
[tex]\%Over\ 50 = 15.625\%[/tex]
Approximate
[tex]\%Over\ 50 = 15.6\%[/tex]
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Given f(x) =x^2 , after performing the following transformations: shift upward 84 units and shift 13 units to the right, the new function g(x) =
g(x) = (x - 13)^2 + 84
= x^2 - 26x + 169 + 84
= x^2 - 26x + 253
What is the value of the x variable in the solution to the following system of equations? (5 points) 2x − 3y = 3 5x − 4y = 4 Select one: a. −1 b. 0 c. x can be any number as there are infinitely many solutions to this system d. There is no x value as there is no solution to this system
Answer:
D. There is no x value as there is no solution to this system
Step-by-step explanation:
2x − 3y = 3 5x − 4y = 4
5x - 4y = 4 -4y = -5x + 4 y = 5/4x - 1
2x - 3(5/4x - 1) = 3
2x - 15/4x + 3 = 3
-7/4x = 0
x = 0
