Answer:
Here we have the matrix:
[tex]M = \left[\begin{array}{ccc}1&0\\0&3\end{array}\right][/tex]
And we want to find its inverse.
The inverse of a 2x2 matrix A is:
(1/det(A))*adj(A)
where det(A) is the determinant of the matrix.
Such that for a matrix:
[tex]A = \left[\begin{array}{ccc}a_{11}&a_{12}\\a_{21}&a_{22}\end{array}\right][/tex]
The determinant is:
det(A) = a₁₁*a₂₂ - a₁₂*a₂₁
in the case of our matrix M, the determinant is:
det(M) = 1*3 - 0*0 = 3
and adj(A) is a transposition along the diagonal, and for the other elements, we just change its sign.
Then for our matrix A we would have:
[tex]adj(A) = \left[\begin{array}{ccc}a_{22}&-a_{12}\\-a_{21}&a_{11}\end{array}\right][/tex]
Then for our matrix M, we have:
[tex]adj(M) = \left[\begin{array}{ccc}3&-0\\-0&1\end{array}\right][/tex]
Then the inverse of the matrix M is:
[tex]M^{-1} = \frac{1}{det(M)} *adj(M) = \frac{1}{3}\left[\begin{array}{ccc}3&0\\0&1\end{array}\right] = \left[\begin{array}{ccc}1&0\\0&1/3\end{array}\right][/tex]
What's an equivalent fraction of 3/4 that has a denominator of 32
Answer:
24/32
Step-by-step explanation:
[tex]\frac{3}{4} = \frac{x}{32}[/tex]
To get from 4 to 32, you multiply by 8
so to get from 3 to x, multiply by 8
The answer for this would be 24/32
PLEASEEEE PLEASEEEE HELPPPP
i need an equation for a vertical line going through f(x) = 2x^2 + 6x + 2
Answer:
dont understand clearly
Step-by-step explanation:
dont understand clearly
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.
The smallest whole number is _______.
Step-by-step explanation:
The smallest whole number is 0 .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
I need help ASAP please!
Answer:
Option C
We need to make the negative exponent positive.
The rule is: [tex]A^{-B} =\frac{1}{A^{B} }[/tex]
Here, A=x, B= 12
[tex]so,[/tex] [tex]x^{-12}[/tex]
[tex]=\frac{1}{x^{12} }[/tex]
OAmalOHopeO
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.
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]
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!
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.
please can anyone help me with this question what is the probability of the spinner landing on an even number.
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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5/10+4/16 in simplest form
Can some please help please thank you
Answer:
D. ( f + g)(x) = 2x^3 + 3x^2 - 5x - 3
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
A rectangular floor is 9 yards long and 3 yards wide. What is the area
Exercise 6.2
1.
a.
The total cost function is given by C = 100 - 5x + 7x2, find
the average cost and marginal cost.
9514 1404 393
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
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:
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]
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
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
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.
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
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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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
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]
Suppose that the number of bacteria in a certain population increases according to a continuous exponential growth model. A sample of 1100 bacteria selected from this population reached the size of 1177 bacteria in three hours. Find the hourly growth rate parameter. Note: This is a continuous exponential growth model. Write your answer as a percentage. Do not round any intermediate computations, and round your percentage to the nearest hundredth.
Answer:
Rate = 10^(log[Ending Amount / Beginning Amount] ÷ time) -1
Rate = 10^(log(1177 / 1100) ÷ time) -1
Rate = 10^(log( 1.07) ÷ 3) -1
Rate = 10^(0.029383777685 /3) -1
Rate = 10^(0.0097945926) -1
Rate = 1.0228091219 -1
Rate = .0228091219% / hour
Source http://www.1728.org/expgrwth.htm
Step-by-step explanation:
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
1/6+4/18 in simplest form
Answer:
7/18
Step-by-step explanation:
1/6 x 3 = 3/18
3/18 + 4/18 = 7/18
Answer:
7/18
Step-by-step explanation:
Make the denominators the same!
You can turn 1/6 into 3/18 by multiplying the numerator and denominator by 3. Then you add the numerators of 3/18 and 4/18 together to get 7/18.
It can't be simplified any further :)
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)
