Mathematics puzzle from my calculus text book.

Answer:

I think its C:37

Step-by-step explanation:

And if im wrong sorry :/

Step-by-step explanation:

Let the husband's income be x

Wife's income be x + 9000

X + X + 9000 = 81000

2X + 9000 – 9000 = 81000 – 9000

2X= 72000

X = 36000

Husband, 36000,

Wife, 9000+36000, 45000

Answer:

2) t distribution with 58 degrees of freedom.

Step-by-step explanation:

Population standard deviations not known:

This means that the t-distribution is used to solve this question.

The sample sizes are n1 = 25 and n2 = 35.

The number of degrees of freedom is the sum of the sample sizes subtracted by the number of samples, in this case 2. So

25 + 35 - 2 = 58 df.

Thus the correct answer is given by option 2.

Answer:

0.9703 = 97.03% probability that 15 or more of them would agree with the claim.

Step-by-step explanation:

For each adult, there are only two possible outcomes. Either they agree with the claim, or they do not. The probability of an adult agreeing with the claim is independent of any other adult, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

75% of adults believe that an unattractive smile hurts career success.

This means that [tex]p = 0.75[/tex]

Suppose that 25 adults are randomly selected.

This means that [tex]n = 25[/tex]

What is the probability that 15 or more of them would agree with the claim?

This is:

[tex]P(X \geq 15) = 1 - P(X < 15)[/tex]

In which:

[tex]P(X < 15) = P(X = 0) + P(X = 1) + P(X = 2) + ... + P(X = 13) + P(X = 14)[/tex]

14 is below the mean, so we start below and go until the probability is 0. Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 14) = C_{25,14}.(0.75)^{14}.(0.25)^{11} = 0.0189[/tex]

[tex]P(X = 13) = C_{25,13}.(0.75)^{13}.(0.25)^{12} = 0.0074[/tex]

[tex]P(X = 12) = C_{25,12}.(0.75)^{12}.(0.25)^{13} = 0.0025[/tex]

[tex]P(X = 11) = C_{25,11}.(0.75)^{11}.(0.25)^{14} = 0.0007[/tex]

[tex]P(X = 10) = C_{25,10}.(0.75)^{10}.(0.25)^{15} = 0.0002[/tex]

[tex]P(X = 9) = C_{25,9}.(0.75)^{9}.(0.25)^{16} \approx 0[/tex]

Then

[tex]P(X < 15) = P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) = 0.0002 + 0.0007 + 0.0025 + 0.0074 + 0.0189 = 0.0297[/tex]

And

[tex]P(X \geq 15) = 1 - P(X < 15) = 1 - 0.0297 = 0.9703[/tex]

0.9703 = 97.03% probability that 15 or more of them would agree with the claim.

To solve this question, the normal distribution and the central limit theorem are used.

Doing this, there is an 0.0129 = 1.29% probability that the mean installation time for 31 computers is less than 43 minutes.

------------------------------------

First, these concepts are presented, then we identify mean, standard deviation and sample size, and then, we find the desired probability.

------------------------------------

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

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

------------------------------------

Mean of 45, standard deviation of 5:

This means that [tex]\mu = 45, \sigma = 5[/tex]

Sample size of 31:

This means that [tex]n = 31, s = \frac{5}{\sqrt{31}}[/tex]

------------------------------------

Probability the sample mean is less than 43:

This is the p-value of Z when X = 43, so:

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

By the Central Limit Theorem

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

[tex]Z = \frac{43 - 45}{\frac{5}{\sqrt{31}}}[/tex]

[tex]Z = -2.23[/tex]

[tex]Z = -2.23[/tex] has a p-value of 0.0129.

Thus, 0.0129 = 1.29% probability that the mean installation time for 31 computers is less than 43 minutes.

A similar question is given at: https://brainly.com/question/15020228

Answer:

Number 1

Step-by-step explanation:

I can answer the first one! The dependent variable is the measurement. The days in the independent and always the X variable

Answer:

Step-by-step explanation:

The measurement of the plant height. That (presumably) is dependent on the amount of fertilizer. Everything else is held constant (such amount of water, amount of sunlight, even distance from a window (constant heat), is held the same for all plants.

(2^-1)^2/2×2^0

2^(-1×2)/2^1

2^-2/2^1

2^(-2-1)

2^(-3)

(1/2)^3

Properties used (m^n)^a = m^na

(m)^-n = (1/m)^n

m^0 = 1

m^n/m^a = m^(n-a)

Must click thanks and mark brainliest

Answer:

smallest is 0 and greatest is 6

simple

Answer:

0 and 6

Step-by-step explanation:

Because 0 is means nothing.And the highest number is 6

9514 1404 393

Answer:

  x = π

Step-by-step explanation:

You want f(g(x)) = g(f(x)):

  3 +cos(2x) = 2(3 +cos(x))

  cos(2x) -2cos(x) = 3 . . . . . . . rearrange

  2cos(x)²-1 -2cos(x) = 3 . . . . . use an identity for cos(2x)

  2(c² -c -2) = 0 . . . . . . . . . . . . substitute c = cos(x)

  (c -2)(c +1) = 0 . . . . . . . . . . . factor

  c = 2 (not possible)

  c = -1 = cos(x) . . . . . true for x = π

The value of x that makes f(g(x)) = g(f(x)) is x = π.

_____

Additional comment

The substitution c=cos(x) just makes the equation easier to write and the form of it easier to see. There is really no other reason for making any sort of substitution. In the end, the equation is quadratic in cos(x), so is solved by any of the usual methods of solving quadratics.

Answer:

The function is always increasing

Step-by-step explanation:

To be increasing, the y value needs to be getting bigger as x gets bigger

This is true for all values of x

The function is increasing for all values of x

Answer:

hhhhjhgbbbjjhjjjjjkkkkkkkk

Answer:

Step-by-step explanation:

Q1. Sobey's is the best deal

In Food Basics, having the two loaves of bread costing 4.88 would mean that (4.88 / 2) one would cost 2.44.

To find out how much three would cost, multiply 2.44 by three, and the result is 7.32, which is higher than the three loves of bread that costs 7.20 in Sobey's, which Sobey's has a better deal. 7.20 / 3 = 2.40, yet Food Basics does cost higher by 4 cents for just one.

I am not too sure about question 2, but I do hope the above question helps!

Answer:

https://brainly.com/question/24258518

Step-by-step explanation:

Answer:

Hello

Step-by-step explanation:

[tex]Formula: \\\\\boxed{\Large a^3\pm b^3=(a \pm b)(a^2 \mp ab+b^2)}\\\\8x^3+1=(2x)^3+1^3=(2x+1)(4x^2-2x+1)\\\\8x^3-1=(2x)^3-1^3=(2x-1)(4x^2+2x+1)\\[/tex]

The factors of the expression 8x³ + 1 and 8x³ - 1³ will be (2x + 1) & (4x² – 2x + 1) and (2x – 1) & (4x² + 2x + 1), respectively.

A polynomial expression is an algebraic expression with variables and coefficients. Unknown variables are what they're termed. We can use addition, subtraction, and other mathematical operations. However, a variable is not divisible.

The expression is given below.

8x³ + 1 and 8x³ - 1³

(2x)³ + 1³ and (2x)³ - 1³

We know that the formula is given as,

a³ + b³ = (a + b) (a² – ab + b²)

a³ – b³ = (a – b) (a² + ab + b²)

Then the expression is written as,

(2x)³ + 1³ = (2x + 1) [(2x)² – 2x + 1²]

(2x)³ + 1³ = (2x + 1) (4x² – 2x + 1)

(2x)³ – 1³ = (2x – 1) [(2x)² + 2x + 1²]

(2x)³ – 1³ = (2x – 1) (4x² + 2x + 1)

The factors of the expression 8x³ + 1 and 8x³ - 1³ will be (2x + 1) & (4x² – 2x + 1) and (2x – 1) & (4x² + 2x + 1), respectively.

More about the polynomial link is given below.

https://brainly.com/question/17822016

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Answer:

-3

Step-by-step explanation:

Slope is equal to (-5-7)/(2-(-2)=-12/4=-3

Answer:

Shade 23 boxes

Step-by-step explanation:

This is the first two rows fully (all 10 boxes) and then three more from the third row.

xxxxxxxxxx

xxxxxxxxxx

xxx . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

. . . . . . . . . .

The 2 triangles are congruent

Answer:

(x+5, y-5) is the correct answer

Step-by-step explanation:

first, take -2 and 3 on x value; when you jump from -2 to 3, your answer is positive 5

second, take 4 and -1 on y value; when you jump from 4 to -1, your answer is negative 5

hence your answer for this question is a- (x+5, y-5)

Answer:

es1433

Step-by-step explanation:

Answer:

120

Step-by-step explanation:

There are 10 possible toppings to choose from, you choose 7.

Using combinatorics, it's 10!/(7! 3!), or 120.

The formula is (total amount to choose from )! divided by (amount you choose)!(amount you don't choose)!

Or search up combination formula

A combination is an arrangement of a set of numbers from a total set where the order of the set is not relevant.

The formula for combination.

= [tex]^nC_r[/tex]

= n! / r! (n -r)!

The number of possible 7-toppings for the pizza is 120.

A combination is an arrangement of a set of numbers from a total set where the order of the set is not relevant.

We have,

The total number of toppings = 10.

n = 10

The number of required toppings = 7.

r = 7

The formula for combination.

= [tex]^nC_r[/tex]

= n! / r! (n -r)!

The possible number of possible 7-toppings pizzas.

= [tex]^{10}C_7[/tex]

= (10 x 9 x 8) / (3 x 2)

= 120

Thus,

n = 10 and r = 7

[tex]^{10}C_7[/tex] = 120

The number of possible 7-toppings for the pizza is 120.

Learn more about combination here:

https://brainly.com/question/14355408

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Considering the given function, we have that:

a) 28.31 years.

b) 0.3382 years a decade.

c) 2.6184.

The median age of the U.S. population in t decades after 1960 is:

f(t) = -0.2176t³ + 1.962t² - 2.833t + 29.4.

1970 is one decade after 1960, hence the median was:

f(1) = -0.2176 x 1³ + 1.962 x 1² - 2.833 x 1 + 29.4 = 28.31 years.

The rate of change was is the derivative when t = 1, hence:

f'(t) = -0.6528t² + 3.924t - 2.933

f'(1) = -0.6528 x 1² + 3.924 x 1 - 2.933 = 0.3382 years a decade.

The second derivative is:

f''(t) = -1.3056t + 3.924

Hence:

f''(1) = -1.3056 x 1 + 3.924 = 2.6184.

More can be learned about functions at https://brainly.com/question/25537936

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Hi there!

To find the Trigonometric Equation, we have to isolate sin, cos, tan, etc. We are also given the interval [0,2π).

First Question

What we have to do is to isolate cos first.

[tex] \displaystyle \large{ cos \theta = - \frac{1}{2} }[/tex]

Then find the reference angle. As we know cos(π/3) equals 1/2. Therefore π/3 is our reference angle.

Since we know that cos is negative in Q2 and Q3. We will be using π + (ref. angle) for Q3. and π - (ref. angle) for Q2.

Find Q2

[tex] \displaystyle \large{ \pi - \frac{ \pi}{3} = \frac{3 \pi}{3} - \frac{ \pi}{3} } \\ \displaystyle \large \boxed{ \frac{2 \pi}{3} }[/tex]

Find Q3

[tex] \displaystyle \large{ \pi + \frac{ \pi}{3} = \frac{3 \pi}{3} + \frac{ \pi}{3} } \\ \displaystyle \large \boxed{ \frac{4 \pi}{3} }[/tex]

Both values are apart of the interval. Hence,

[tex] \displaystyle \large \boxed{ \theta = \frac{2 \pi}{3} , \frac{4 \pi}{3} }[/tex]

Second Question

Isolate sin(4 theta).

[tex] \displaystyle \large{sin 4 \theta = - \frac{1}{ \sqrt{2} } }[/tex]

Rationalize the denominator.

[tex] \displaystyle \large{sin4 \theta = - \frac{ \sqrt{2} }{2} }[/tex]

The problem here is 4 beside theta. What we are going to do is to expand the interval.

[tex] \displaystyle \large{0 \leqslant \theta < 2 \pi}[/tex]

Multiply whole by 4.

[tex] \displaystyle \large{0 \times 4 \leqslant \theta \times 4 < 2 \pi \times 4} \\ \displaystyle \large \boxed{0 \leqslant 4 \theta < 8 \pi}[/tex]

Then find the reference angle.

We know that sin(π/4) = √2/2. Hence π/4 is our reference angle.

sin is negative in Q3 and Q4. We use π + (ref. angle) for Q3 and 2π - (ref. angle for Q4.)

Find Q3

[tex] \displaystyle \large{ \pi + \frac{ \pi}{4} = \frac{ 4 \pi}{4} + \frac{ \pi}{4} } \\ \displaystyle \large \boxed{ \frac{5 \pi}{4} }[/tex]

Find Q4

[tex] \displaystyle \large{2 \pi - \frac{ \pi}{4} = \frac{8 \pi}{4} - \frac{ \pi}{4} } \\ \displaystyle \large \boxed{ \frac{7 \pi}{4} }[/tex]

Both values are in [0,2π). However, we exceed our interval to < 8π.

We will be using these following:-

[tex] \displaystyle \large{ \theta + 2 \pi k = \theta \: \: \: \: \: \sf{(k \: \: is \: \: integer)}}[/tex]

Hence:-

For Q3

[tex] \displaystyle \large{ \frac{5 \pi}{4} + 2 \pi = \frac{13 \pi}{4} } \\ \displaystyle \large{ \frac{5 \pi}{4} + 4\pi = \frac{21 \pi}{4} } \\ \displaystyle \large{ \frac{5 \pi}{4} + 6\pi = \frac{29 \pi}{4} }[/tex]

We cannot use any further k-values (or k cannot be 4 or higher) because it'd be +8π and not in the interval.

For Q4

[tex] \displaystyle \large{ \frac{ 7 \pi}{4} + 2 \pi = \frac{15 \pi}{4} } \\ \displaystyle \large{ \frac{ 7 \pi}{4} + 4 \pi = \frac{23\pi}{4} } \\ \displaystyle \large{ \frac{ 7 \pi}{4} + 6 \pi = \frac{31 \pi}{4} }[/tex]

Therefore:-

[tex] \displaystyle \large{4 \theta = \frac{5 \pi}{4} , \frac{7 \pi}{4} , \frac{13\pi}{4} , \frac{21\pi}{4} , \frac{29\pi}{4}, \frac{15 \pi}{4} , \frac{23\pi}{4} , \frac{31\pi}{4} }[/tex]

Then we divide all these values by 4.

[tex] \displaystyle \large \boxed{\theta = \frac{5 \pi}{16} , \frac{7 \pi}{16} , \frac{13\pi}{16} , \frac{21\pi}{16} , \frac{29\pi}{16}, \frac{15 \pi}{16} , \frac{23\pi}{16} , \frac{31\pi}{16} }[/tex]

Let me know if you have any questions!

9514 1404 393

Answer:

  x = 14 cm

Step-by-step explanation:

We can only solve for x if the triangles are similar. The arrows on the left and right legs say those are parallel. Since alternate interior angles at each of the transversals are congruent, the triangles are AA similar.

ΔABC ~ ΔDEC, so we have ...

  EC/ED = BC/BA

  x/(18 cm) = (35 cm)/(45 cm)

  x = (18 cm)(7/9) = 14 cm

Answer:

total number of boys in skool is 216

And

ratio of girls to boys is a 3:4

Step-by-step explanation:

let total no. of boys be X

ACCORDING TO QUESTION

ratio of boys to girls = 4:3

total number of girls = 162

now

4/3=X/162

or, 4×162= 3x

or, 4×162/3= X

hence

X = 216

therefore total number of boys is 216

and

ratio of girls to boys is =162/216

=3/4

=3:4

Answer:

60

Step-by-step explanation:

Use similar triangles or the ratios from the right triangle altitude theorem.

x/36 = (64 + 36)/x

x² = 3600

x = 60

Answer:

I'm not sure if the kite outside has at least a pair of equal sides. The rest I think are right though? Correct me if I'm wrong.

Answer:

x=  $6,284.15

Step-by-step explanation:

7300 = x(1 + .025/12)^72

x = [tex]\frac{7300}{(1 + \frac{.025}{12} )^{72} }[/tex]

x=  $6,284.15  

Answer:

1/52

Step-by-step explanation:

Answer:

1.D

2.B

Step-by-step explanation:

1. The x intercept is the value of x when y is zero. We know that the x intercept is 0.5 so we must find a value of k that will make our rational function equal zero when x=0.5

[tex]y = \frac{k}{x + 1} - 2[/tex]

Substitute x=0.5 and y=0.

[tex]0 = \frac{k}{0.5 + 1} - 2[/tex]

[tex]0= \frac{k}{1.5} - 2[/tex]

[tex]2 = \frac{k}{1.5} [/tex]

[tex]3 = k[/tex]

D is the Answer.

2. We need to consider the function

[tex] \frac{2x}{1 - {x}^{2} } [/tex]

Since the numerator is a linear term, it will have one zero to the equation using fundamental Theorem of Algebra so C is wrong.

This is a rational function because we are dividing two polynomials by each other and q(x) or the denominator isnt zero. So D is wrong.

The denominator is a quadratic term so it will have two vertical asymptote according to the fundamental Theorem of Algebra So A is Wrong.

B is Right, the equation isnt defined at x=0 because when we plug 0 into the denominator, it doesn't equate to zero.

this is a special triangle so v = 17

u = 17√2

Answer:

v = 17

u = 17[tex]\sqrt{2}[/tex]

Step-by-step explanation:

If v = 17 (it is because it is a right triangle, so the pythagorean theorum works, and triangles are 180 degrees, so 180 - 90 = 90, so the other two angles are 45 degrees, meaning that v is the same length as 17.) then

17 ^ 2 = u ^2

289 = u^2

17 root to 2

Answer:

8 months 11 days 1 year