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2 years ago

Alvin and Bala has 26 stickers.Alvin had 8 more stickers thab Bala.How many stickers did Bala have?

1 answer:

3 0

Bala had 9 stickers

You could set this up as a equation. Because there was a total of 26 you would for sure put =26. Next you are told Alvin has 8 MORE than Bali, therefore you would be adding the unknown value of Bala by 8. This could be represented as x+8=26. Now that you have x added to 8 you need to add another x to the equation to fully represent the problem since Alvin has 8 more stickers than Bala does. The new equation would become 2x+8=26.

You must now isolate x by first subtraction 8 from both sides which will leave you with 2x=18. Then you divide on both sides by 2 and will leave you with x=9

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The equation d = can be used to calculate the density, d, of an object with mass, m, and volume, V. Which is an equivalent equat

Kamila [148]

Since:
Density=Mass/Volume
Mass=Volume*Density
Therefore, Volume=Mass/Density

4 0

2 years ago

Read 2 more answers

A probability calculator is required on this problem; answer to six decimal places. Suppose we will spin the wheel pictured 400

KiRa [710]

Answer:

$P(90< X< 110)= P(\frac{90-80}{8}$

And we can find this probability with this difference:

$P(90< X< 110)=P(z$

And we can find the real value with the following excel code using the binomial distribution:

"=BINOM.DIST(110,400,0.2,TRUE)-BINOM.DIST(89,400,0.2,TRUE)"

And we got 0.118 a very close value from the value obtained using the normal approximation

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=400, p=0.2)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

We need to check the conditions in order to use the normal approximation.

$np=400*0.2=80 \geq 10$

$n(1-p)=400*(1-0.2)=320 \geq 10$

So we see that we satisfy the conditions and then we can apply the approximation.

If we appply the approximation the new mean and standard deviation are:

$E(X)=np=400*0.2=80$

$\sigma=\sqrt{np(1-p)}=\sqrt{400*0.2(1-0.2)}=8$

So then we can approximate the random variable as $X \sim N(\mu = 80, \sigma = 8)$

And we want this probability:

$P(90< X< 110)$

We can use the z score formula given by:

$z = \frac{x -\mu}{\sigma}$

And replacing we got:

$P(90< X< 110)= P(\frac{90-80}{8}$

And we can find this probability with this difference:

$P(90< X< 110)=P(z$

And we can find the real value with the following excel code using the binomial distribution:

"=BINOM.DIST(110,400,0.2,TRUE)-BINOM.DIST(89,400,0.2,TRUE)"

And we got 0.118 a very close value from the value obtained using the normal approximation

8 0

2 years ago

the length of the rectangle is measured as 370mm correct to 2 significant figures.a) what is the upper bound for the length?the

ivanzaharov [21]

Answer:

a) 375

b) 7062.75 mm²

Step-by-step explanation:

b) We need to find the shortest possible width and length to get the smallest possible area.

To get the boundaries for 19.4, we go on to the next significant figure (the hundredths) and ± 5 of them.

The boundaries are, therefore: 19.35 - 19.45

As for the length, we can see they've added 5 units as the measurement is correct to 2 sig' figures, which is the tens.

And so, if we do as we did before, we go to the next sig' figure (the units) and ± 5 of them, we get the boundaries to be 365 - 375.

Now, we just multiply the lower bounds of the length and width to get the minimal/lower-bound area:

365 * 19.35 = 7062.75 mm²

7 0

1 year ago

The harmonic motion of a particle is given by f(t) = 2 cos(3t) + 3 sin(2t), 0 ≤ t ≤ 8. (a) When is the position function decreas

iren [92.7K]

For the last part, you have to find where $f'(t)$ attains its maximum over $0\le t\le8$ . We have

$f'(t)=-6\sin3t+6\cos2t$

so that

$f''(t)=-18\cos3t-12\sin2t$

with critical points at $t$ such that

$-18\cos3t-12\sin2t=0$

$3\cos3t+2\sin2t=0$

$3(\cos^3t-3\cos t\sin^2t)+4\sin t\cos t=0$

$\cos t(3\cos^2t-9\sin^2t+4\sin t)=0$

$\cos t(12\sin^2t-4\sin t-3)=0$

So either

$\cos t=0\implies t=\dfrac{(2n+1)\pi}2$

$12\sin^2t-4\sin t-3=0\implies\sin t=\dfrac{1\pm\sqrt{10}}6\implies t=\sin^{-1}\dfrac{1\pm\sqrt{10}}6+2n\pi$

where $n$ is any integer. We get 8 solutions over the given interval with $n=0,1,2$ from the first set of solutions, $n=0,1$ from the set of solutions where $\sin t=\dfrac{1+\sqrt{10}}6$ , and $n=1$ from the set of solutions where $\sin t=\dfrac{1-\sqrt{10}}6$ . They are approximately

$\dfrac\pi2\approx2$

$\dfrac{3\pi}2\approx5$

$\dfrac{5\pi}2\approx8$

$\sin^{-1}\dfrac{1+\sqrt{10}}6\approx1$

$2\pi+\sin^{-1}\dfrac{1+\sqrt{10}}6\approx7$

$2\pi+\sin^{-1}\dfrac{1-\sqrt{10}}6\approx6$

4 0

2 years ago

A person is standing 50 ft from a statue. The person looks up at an angle of elevation of 8o when staring at the top of the stat

Lyrx [107]

Answer:

$h=50.25\ ft$

Step-by-step explanation:

<u>Right Triangles </u>

In a right triangle, one of the internal angles is 90°. When this happens, there is always a longer side, called hypotenuse and two shorter sides, called legs. They relate to Pythagoras's theorem. The basic trigonometric relations also stand, including

$\displaystyle tan\alpha=\frac{a}{c}$

where a is the opposite leg to $\alpha$ and c is its adjacent led .

In our problem, we have a statue being looked by a person in such a way that the top of the statue forms an angle of 8° with the horizontal and the base of the statue forms an angle of 14° down. We also know the distance from the person to the statue is 50 ft. The situation is shown in the image below.

The height of the statue is h=a+b, where

$a=50tan8^o$