Suppose A is a 5times7 matrix. How many pivot columns must A have if its columns span set of real numbers RSuperscript 5​? ​Why?

Answer:

45°

Step-by-step explanation:

The diagram for this question has been attached to this response. Please check.

The angle of elevation is the angle between a horizontal line from a viewer and the line of sight to an object being viewed which is above the horizontal line.

From the diagram;

θ is the angle of elevation

x = height of the tree

y = length of the shadow of the tree = x

Therefore,

tanθ = [tex]\frac{x}{y}[/tex]           [Remember that y = x? Then substitute into the equation]

tanθ = [tex]\frac{x}{x}[/tex]

tanθ = 1

θ = tan⁻¹(1)

θ = 45°

Therefore, the angle of elevation is 45°

The tangent vector to r(t) at any t in the domain is

[tex]\mathbf T(t)=\dfrac{\mathrm d\mathbf r(t)}{\mathrm dt}=2\cos t\,\mathbf i-7\sin t\,\mathbf j[/tex]

At t = π/6, the tanget vector is

[tex]\mathbf T\left(\dfrac\pi6\right)=\sqrt3\,\mathbf i-\dfrac72\,\mathbf j[/tex]

To get the unit tangent, normalize this vector by dividing it by its magnitude:

[tex]\left\|\mathbf T\left(\dfrac\pi6\right)\right\|=\sqrt{(\sqrt3)^2+\left(-\dfrac72\right)^2}=\dfrac{\sqrt{61}}2[/tex]

So the unit tangent at the given point is

[tex]\dfrac{\mathbf T\left(\frac\pi6\right)}{\left\|\mathbf T\left(\frac\pi6\right)\right\|}=2\sqrt{\dfrac3{61}}\,\mathbf i-\dfrac7{\sqrt{61}}\,\mathbf j[/tex]

Applying derivatives, the tangent vector of unit length at the point given is:

[tex]r_{u}{\prime}(\frac{\pi}{6}) = \frac{2\sqrt{3}}{\sqrt{61}}i - \frac{7}{\sqrt{61}}j[/tex]

The vector function is:

[tex]r(t) = 2\sin{(t)}i + 7\cos{(t)}j[/tex]

The tangent vector is it's derivative, which is given by:

[tex]r^{\prime}(t) = 2\cos{(t)}i - 7\sin{(t)}j[/tex]

At point [tex]t = \frac{\pi}{6}[/tex], we have that:

[tex]r^{\prime}(\frac{\pi}{6}) = 2\cos{(\frac{\pi}{6})}i - 7\sin{(\frac{\pi}{6})}j[/tex]

[tex]r^{\prime}(\frac{\pi}{6}) = \frac{2\sqrt{3}}{2}i - \frac{7}{2}[/tex]

[tex]r^{\prime}(\frac{\pi}{6}) = \sqrt{3}i - \frac{7}{2}[/tex]

The norm of the vector is:

[tex]|r^{\prime}(\frac{\pi}{6})| = \sqrt{\sqrt{3}^2 + (-\frac{7}{2})^2}[/tex]

[tex]|r^{\prime}(\frac{\pi}{6})| = \sqrt{\frac{61}{4}}[/tex]

[tex]|r^{\prime}(\frac{\pi}{6})| = \frac{\sqrt{61}}{2}[/tex]

The unit vector is given by each component divided by the norm, thus:

[tex]r_{u}{\prime}(\frac{\pi}{6}) = \frac{\sqrt{3}}{\frac{\sqrt{61}}{2}}i - \frac{7}{2\frac{\sqrt{61}}{2}}j[/tex]

[tex]r_{u}{\prime}(\frac{\pi}{6}) = \frac{2\sqrt{3}}{\sqrt{61}}i - \frac{7}{\sqrt{61}}j[/tex]

A similar problem is given at https://brainly.com/question/20733439

Answer:

0.0885 = 8.85% probability that the sample mean will exceed 2,500.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes 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]

In this question:

[tex]\mu = 2400, \sigma = 210, n = 8, s = \frac{210}{\sqrt{8}} = 74.25[/tex]

Calculate the probability that the sample mean will exceed 2,500.

This is 1 subtracted by the pvalue of Z when X = 2500. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{2500 - 2400}{74.25}[/tex]

[tex]Z = 1.35[/tex]

[tex]Z = 1.35[/tex] has a pvalue of 0.9115

1 - 0.9115 = 0.0885

0.0885 = 8.85% probability that the sample mean will exceed 2,500.

Answer:

34.99

Step-by-step explanation:

Answer:

$72

Step-by-step explanation:

I = Prt

I = ($300)(0.04)(6)

I = $72

Answer:

1050 in total, 52.50 for each athlete

Step-by-step explanation:

We can start by writing an equation with x as the number of athletes

250+40x= Total cost

Now we can substitute 20 for x

250+40(20)

250+800

1050

The total cost is 1050

If you need the amount that each athlete is paying individually, just divide it by 20

1050/20=52.50

52.50 for each athlete

Answer:  Q(x) = x² - 4x + 2

Step-by-step explanation:

P(x) · Q(x) = R(x)   ⇒   Q(x) = R(x)/P(x)

R(x) = x³ - 2x² - 6x + 4     ÷     P(x) = x + 2

I will use synthetic division (but you can also use long division).

-2 |  1     -2     -6     4  

    |  ↓    -2       8    -4  

       1    -4       2      0   ← remainder

The reduced polynomial is: x² - 4x + 2

Answer:

Option D (20) is the right answer.

Step-by-step explanation:

The given values are:

Length of wood,

= 78 inches

Wood pieces,

=  [tex]3\frac{3}{4} \ inches[/tex]

On converting this in proper fraction, we get

=  [tex]3\frac{3}{4}[/tex]

=  [tex]\frac{15}{4}[/tex]

=  [tex]3.75 \ inches[/tex]

Now,

On dividing "78" from "3.78", we get

=  [tex]\frac{78}{3.75}[/tex]

=  [tex]20.8 \ pieces[/tex]

So we got "20 pieces".

Answer:

  4 blue fish for every 5 orange fish

Step-by-step explanation:

(orange fish) = (1 1/4)·(blue fish) . . . . . the given relation

(orange fish) = (5/4)·(blue fish) . . . . . write as improper fraction

(orange fish)/(blue fish) = 5/4  . . . . .  divide by "blue fish"

There are 4 blue fish for every 5 orange fish.

Answer: 72 arrangements

Step-by-step explanation:

The books are:

Statistics,  calculus, geometry, algebra, and trigonometry.

So we have 5 books.

We want that algebra and trigonometry are not together.

Suppose that we have 5 positions:

Now, we can start with algebra in the first position.

Now, we have 3 positions for trigonometry (3rd, 4th and 5th).

Now, once those two books are in position, we have 3 other positions and 3 other books, so for the first selection we have 3 options, for the second position we have 2 options, and for the last option we have 1 option.

The number of combinations is equal to the number of options in each selection:

3*(3*2*1) = 18

Now, if Algebra is in the second place, then for trigonometry we have only 2 possible options (4th and 5th)

and for the other 3 books again we have 3*2*1 combinations:

the total number of combinations is:

2*(3*2*1) = 12

If algebra is in the 3rd position, trigonometry has 2 options (1st and 5th)

For the other 3 books, we have 3*2*1 combinations.

The total number of combinations is:

(3*2*1)*2 = 12

in the fourth position is the same as the second position, so here we have again 12 combinations.

For the fifth position is the same as for the first position, so we have 18 combinations.

The total number of combinations is:

C = 18 + 12 +12 +12 +18 = 72

Answer:

Always true

Step-by-step explanation:

Trust me

Answer:

true

Step-by-step explanation:

Answer:c is the correct ans

Step-by-step explanation:

Feel pleasure to help u

Answer:

B-. More than one unique triangle exists with the given side lengths.

Step-by-step explanation:

according to to tringle inequality theorem he sum of the length of two sides of a triangle should be greater than the third side”. In order to verify the mentioned theorem, some cal. are preforemed below

12+15>18

15+18>12

Answer:

A.

Step-by-step explanation:

B is wrong because irrational numbers can include pie.

C and D are wrong because irrational numbers don't get a whole number, and instead gives a decimal numbers.

Answer:

67/100

Step-by-step explanation:

Find common denominators, note that what you do to the denominator, you must do to the numerator.

The common denominator is 100:

(3/10)(10/10) = (3 * 10)/(10 * 10) = 30/100

Add:

37/100 + 30/100 = 67/100

67/100 is your answer.

~

Answer:

67/100

Step-by-step explanation:

37/100+3/10

Get a common denominator

37/100 + 3/10 *10/10

37/100+30/100

67/100

Answer:  6x² + 11

Step-by-step explanation:

  24x³ - 54x²    +    44x - 99

=  6x²(4x - 9)     +    11(4x - 9)

=  (6x² + 11) (4x - 9)

This can be rewritten as: 4x(6x² + 11) - 9(6x² + 11)

This is the answer to your problem.

Answer:

C

Step-by-step explanation:

The equation must be equal to c since that is the total cost.

c = 1.18v

Plug in 98 for v to find the answer.

c = 1.18(98)

c = $115.64

Answer:

Convert [tex]\frac{2}{3}[/tex] to an improper fraction.

So your answer is [tex]\frac{11}{3}[/tex]

Step-by-step explanation:

Hope this helped you!!

━━━━━━━☆☆━━━━━━━

▹ Answer

[tex]\frac{11}{3}[/tex]

▹ Step-by-Step Explanation

3 * 3 = 9

9 + 2 = 11

Therefore, the answer is 11/3.

Hope this helps!

- CloutAnswers ❁

Brainliest is greatly appreciated!

━━━━━━━☆☆━━━━━━━

Answer:

Step-by-step explanation:

Hello!

The given data corresponds to the variables

Y:  Annual Maintenance  Expense ($100s)

X: Weekly Usage  (hours)

n= 10

∑X= 253; ∑X²= 7347; [tex]\frac{}{X}[/tex]= ∑X/n= 253/10= 25.3 Hours

∑Y= 346.50; ∑Y²= 13010.75; [tex]\frac{}{Y}[/tex]= ∑Y/n= 346.50/10= 34.65 $100s

∑XY= 9668.5

a)

To estimate the slope and y-intercept you have to apply the following formulas:

[tex]b= \frac{sumXY-\frac{(sumX)(sumY)}{n} }{sumX^2-\frac{(sumX)^2}{n} } = \frac{9668.5-\frac{253*346.5}{10} }{7347-\frac{(253)^2}{10} }= 0.95[/tex]

[tex]a= \frac{}{Y} -b\frac{}{X} = 34.65-0.95*25.3= 10.53[/tex]

^Y= a + bX

^Y= 10.53 + 0.95X

b)

H₀: β = 0

H₁: β ≠ 0

α:0.05

[tex]F= \frac{MS_{Reg}}{MS_{Error}} ~~F_{Df_{Reg}; Df_{Error}}[/tex]

F= 47.62

p-value: 0.0001

To decide using the p-value you have to compare it against the level of significance:

If p-value ≤ α, reject the null hypothesis.

If p-value > α, do not reject the null hypothesis.

The decision is to reject the null hypothesis.

At a 5% significance level you can conclude that the average annual maintenance expense of the computer wheel alignment and balancing machine is modified when the weekly usage increases one hour.

b= 0.95 $100s/hours is the variation of the estimated average annual maintenance expense of the computer wheel alignment and balancing machine is modified when the weekly usage increases one hour.

a= 10.53 $ 100s is the value of the average annual maintenance expense of the computer wheel alignment and balancing machine when the weekly usage is zero.

c)

The value that determines the % of the variability of the dependent variable that is explained by the response variable is the coefficient of determination. You can calculate it manually using the formula:

[tex]R^2 = \frac{b^2[sumX^2-\frac{(sumX)^2}{n} ]}{[sumY^2-\frac{(sumY)^2}{n} ]} = \frac{0.95^2[7347-\frac{(253)^2}{10} ]}{[13010.75-\frac{(346.50)^2}{10} ]} = 0.86[/tex]

This means that 86% of the variability of the annual maintenance expense of the computer wheel alignment and balancing machine is explained by the weekly usage under the estimated model ^Y= 10.53 + 0.95X

d)

Without usage, you'd expect the annual maintenance expense to be $1053

If used 100 hours weekly the expected maintenance expense will be 10.53+0.95*100= 105.53 $100s⇒ $10553

If used 1000 hours weekly the expected maintenance expense will be $96053

It is recommendable to purchase the contract only if the weekly usage of the computer is greater than 100 hours weekly.

Answer:

There are 10 digits and 6 numbers so the answer is 10 * 10 * 10 * 10 * 10 * 10 = 10⁶ = 1,000,000.

Answer:

Hello There!

~~~~~~~~~~~~~~~~~~~`

The height of the blimp over the football stadium = 161.9 yards

Hope this helepd you. Brainliest would be nice!

Answer:

Step-by-step explanation:

First convert 3 minutes and 15 seconds into minutes by converting 15 sec to min and add it to 3min

60 sec = 1min

15 sec = 15 / 60 × 1 min

= 0.25min

Add it to 3min

3min + 0.25min = 3.25 min

We use ratio and proportion

3.25min = 104 copies

1 min = 104× 1/ 3.25

= 104 / 3.25

= 32

The final answer is 32 copies

Hope this helps you.

Answer:

Step-by-step explanation:

3 min 15 sec = 3*60 + 15 = 180 + 15 = 195 seconds

In 195 seconds 104 copies are made

In one second, the number of copies made = [tex]\frac{104}{195}\\[/tex]

In 60 seconds, the number of copies made = [tex]\frac{104}{195}*60[/tex]

                                                                       = 32 copies

Answer:

b. 1.69

Step-by-step explanation:

So to solve this problem we need to simply find the percentage increase from 11.8 to 12 =>

to solve this we would do 12 - 11.8 = 0.2 --> 0.2 is our "difference in the increase" -->

now we divide this by our amt. which is 11.8 --> 0.2/11.8 = approx. 0.0169

--> finally multiply that by 100 which is simply moving the decimal places 2 places right giving us the final answer of 1.69

Hope this helps!

Answer:

B. 1.69%

Step-by-step explanation:

If Ross calculated the countertop for a laundry room to be 12 square feet but turns out to be actually 11.8 square feet, we need to find out how much percentage error Ross has made!

In order to solve this question,

1) We need to create proportions:

Ross' calculations              x

______________ =   _________

   actual area                   100

x represents the percentage error.

100 is the total percentage.

2) Now we plug in the numbers:

We plug in 12 for Ross' calculations. We plug in 11.8 for the actual area. So, it will look like this:

   12                x

______ = _______

   11.8           100

3) Time for cross multiplication:

12 times 100 is 1,200

11.8 times x is 11.8x

So,

1,200 = 11.8x

4) Now we divide:

1,200 divided by 11.8 equals to 101.69 %

5) We are not done! We still have to subtract:

101.69

-100.00

_______

    1.69

Finished!!

Our answer is 1.69%, which is B.

Hope this was helpful !!!

Answer:

The test statistic used to determine whether a particular predictor in a regression analysis is statistically significant is:

[tex]t=\frac{\beta_{i}}{S.E._{\beta_{i}}}[/tex]

Step-by-step explanation:

The general form of a regression equation is:

[tex]y=\alpha +\beta_{1}x_{1}+\beta_{2}x_{2}+...+\beta_{n}x_{n}[/tex]

Here,

α = y-intercept

βi = regression coefficients, (i = 1, 2, ..., n)

A regression analysis is performed to determine whether the predictor variables are statistically significant or not.

The output of the regression analysis consists of two tables.

One is the regression output and the other is the ANOVA table.

The regression output table is used to display which predictor variables are statistically significant and which are not.

The test statistic used to determine whether a particular predictor in a regression analysis is statistically significant is:

[tex]t=\frac{\beta_{i}}{S.E._{\beta_{i}}}[/tex]

And the ANOVA table displays overall regression analysis.

The F-test statistic is used to for the overall regression analysis.

Thus, the test statistic used to determine whether a particular predictor in a regression analysis is statistically significant is:

[tex]t=\frac{\beta_{i}}{S.E._{\beta_{i}}}[/tex]

Answer: 2.04÷ 4= 0.51

4.68÷9= 0.52

4 pack is better value by 0.01

Answer:

creat a t-chart to graph the coordinates.

Answer:

The sales tax is 2.10

Step-by-step explanation:

Take the price of the item and multiply by the sales tax rate to determine the tax

30 * 7%

30 * .07

2.10

The sales tax is 2.10

Answer:

^Y= 26.72 + 0.0547Xi

^Y/[tex]_{X=3000}[/tex]= 190.82ºF

B. It is unrealistically high.

Step-by-step explanation:

Hello!

*Full text*

The data show the bug chirps per minute at different temperatures. Find the regression equation, letting the first variable be the independent (x) variable. Find the best predicted temperature for a time when a bug is chirping at the rate of 3000 chirps per minute. Use a significance level of .05. What is wrong with this predicted value?

Chirps in 1 min.     929    854    771    1004    1201    1027

Temperature (F)     81.3    77.3    64.8    80.3    92.2    80.9

What is the regression equation?

^y= _____ + _____

(Round the x-coefficient to four decimal places as needed. Round the constant to two decimals as needed)

What is the predicted value? ^y= _____ (Round to one decimal places as needed)

What is wrong with this predicted value?

A. The first variable should have been the dependent variable

B. It is unrealistically high.

C. It is only an approximation

D. Nothing is wrong with this value

To calculate the regression equation you have to estimate the slope and the y-intercept.

^Y= a + bX

Estimate of the slope:

[tex]b= \frac{sumXY-\frac{(sumX)(sumY)}{n} }{sumX^2-\frac{(sumX)^2}{n} }[/tex]

n= 6

∑X= 5786 ∑X²= 5691944 [tex]\frac{}{X}[/tex]= 964.33

∑Y= 476.80 ∑Y²= 38277.76 [tex]\frac{}{Y}[/tex]= 79.47

∑XY= 465940.4

[tex]b= \frac{465940.4-\frac{5786*476.80}{6} }{5691944-\frac{(5786)^2}{6} }= 0.0547[/tex]

Estimate of the Y-intercept:

[tex]a= \frac{}{Y} -b*\frac{}{X}[/tex]

[tex]a= 79.47 -0.0547*964.33= 26.696= 26.72[/tex]

The estimated regression equation is:

^Y= 26.72 + 0.0547Xi

^Y/[tex]_{X=3000}[/tex]= 26.72 + 0.0547*3000= 190.82ºF

At the rate of 3000 chirps per minute it is expected a temperature of 190.82ºF

As you can see it is unrealistic to think that the chirping rate of bugs will have any effect over the temperature. For what is known about bugs, they tend to be more active to higher temperatures.

Considering the value obtained, as it is incredible high, if this regression was correct, every time the chirping rate of bugs increases, the ambient temperature would rise to levels incompatible with life.

I hope this helps!

Answer:

$36

Step-by-step explanation:

30 is 5/6 of the game, so we can think that 1/6 is equal to 6, since 5(6) is 30.

If we add another sixth, we get 36, which will be the total cost of the game.

Answer:

Step-by-step explanation:

First of all, we need to define the image and pre-image.

Second, let's write down the coordinates of each rectangle.

ABCD coordinates:

A(-6,5)

B(-1,5)

C(-1,1)

D(-6,1)

A'B'C'D' coordinates:

A'(5,-1)

B'(5,-6)

C'(1,-6)

D'(1,-1)

The first rule we need to apply is the 90° clockwise rotation which is

[tex](x,y) \implies (y,-x)[/tex]

Which gives us (5,6), (5,1), (1,1), (1,6).

Then, we use the 7 units-down rule

[tex](x,y) \implies (x,y-7)[/tex]

Which gives us (5,-1), (5,-6), (1,-6) and (1,-1).

Therefore, the right answer is the third choice.

Answer:

A 90° clockwise rotation about the origin and a translation of 7 units down.

Answer:

  CA = 5

Step-by-step explanation:

Since the sides are 3 and 4, we recognize this as a 3:4:5 right triangle, with CA = 5. Using the Pythagorean theorem confirms this:

  CA² = AB² +BC²

  CA² = 3² +4² = 9 +16 = 25

  CA = √25

  CA = 5

Answer:

D. CA = 5

Step-by-step explanation:

The Pythagorean Theorem states that given a right triangle with legs a and b and hypotenuse (longest side) c:

a² + b² = c²

Here, the legs are 3 and 4, so a = 3 and b = 4. Plug these in to find c:

a² + b² = c²

3² + 4² = c²

9 + 16 = c²

25 = c²

c = √25 = 5

The answer is thus D.

~ an aesthetics lover