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4 years ago

Find 93 • 87 using mental math.

2 answers:

7 0

Okay so start with multiplying 93 * 7

So 3 x 7= 21

9 X 7 +63, carry the 2 = 651

Then 8 x 93
Remember that first is a zero.
8 X 3= 24
8 X 9= 72, carry the 2= 74
So that is 7440
Now
0651
+7440
8091
And that's the answer

charle [14.2K]4 years ago

5 0

Answer: 8091

Step-by-step explanation:

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A school guidance counselor is researching the number of high school students who play an online video game that is aimed at muc

ycow [4]

Answer:

C is the answer

Step-by-step explanation:

3 0

3 years ago

5. In a right triangle, the sum of the lengths of the two legs is 100 meters. What are the lengths of the three sides

LiRa [457]

Answer:

6m by 8m by 10m

Step-by-step explanation:

6²+8²= 100

36+64=100

100=100

5 0

3 years ago

Exercise 5.2. Suppose that X has moment generating function

soldi70 [24.7K]

Answer:

a) Mean, E(X) = - 0.5

Variance = = 9.25

b) $M_{X}(t)=E(e^{tX})$

⇒ $=\sum e^{tx}p(x)$

⇒ $=\frac{1}{2}+\frac{1}{3}e^{-4t}+\frac{1}{6}e^{5t}$

Step-by-step explanation:

Given:

moment generating function of X as:

MX(t) = $\frac{1}{2} + \frac{1}{3}e^{-4t} + \frac{1}{6} e^{5t}$

a) Now

Mean, E(X) = $M_{X}'(t=0)$

Thus,

$M_{X}'(t)=\frac{1}{3}(-4)e^{-4t}+\frac{1}{6}(5)e^{5t}$

$M_{X}'(t)=\frac{-4}{3}e^{-4t}+\frac{5}{6}e^{5t}$

also,

$E(X^{2})=M_{X}''(t=0)$

Thus,

$M_{X}''(t)=\frac{-4}{3}(-4)e^{-4t}+\frac{5}{6}(5)e^{5t}$

$M_{X}''(t)=\frac{16}{3}e^{-4t}+\frac{25}{6}e^{5t}$

Therefore,

Mean, E(X) = $M_{X}'(t=0)=\frac{-4}{3}e^{-4(0)}+\frac{5}{6}e^{5(0)}$

Mean, E(X) = - 0.5

and

$E(X^{2})=M_{X}''(t=0)=\frac{16}{3}e^{-4(0)}+\frac{25}{6}e^{5(0)}$

$E(X^{2})$ = 9.5

also,

Variance(X) = E(X²) - E(X)²

⇒ 9.5 - (-0.5)²

= 9.25

b) Now,

Let f(x) be the PMF of X

Thus,

$M_{X}(t)=E(e^{tX})$

⇒ $=\sum e^{tx}p(x)$

⇒ $=\frac{1}{2}+\frac{1}{3}e^{-4t}+\frac{1}{6}e^{5t}$

Therefore,

at x = 0, P(x) = $\frac{1}{2}$

at x= - 4 ,P(x) = $\frac{1}{3}$

at x = 5, P(x) = $\frac{1}{6}$

Thus,

E(X) = $\sum xP(x)=0(\frac{1}{2})+(-4)(\frac{1}{3})+5(\frac{1}{6})$

E(X) = - 0.5

also, $E(X^{2})=\sum x^{2}P(x)=0^{2}(\frac{1}{2})+(-4)^{2}(\frac{1}{3})+5^{2}(\frac{1}{6})$

$E(X^{2})$ = 9.5

Hence,

Var(X) = E(X²) - E(X)²

⇒ 9.5 - (-0.5)²

= 9.25

4 0

4 years ago

What degree slope is a 16' ramp with a 35" rise

masha68 [24]

Answer:

10.5 Degree.

Step-by-step explanation:

The inclined length of the ramp is 16' i.e. 16 feet i.e. (16 × 12) = 192 inches.

And the rise of the ramp is 35" i.e. 35 inches.

We have to calculate the degree of slope from the above information.

If we consider the ramp as the hypotenuse of a right triangle, then the perpendicular height is 35 inches.

Then angle of slope is given by

$\sin \theta = \frac{Perpendicular}{Hypotenuse} = \frac{35}{192} = 0.182$

⇒ $\theta =\sin^{-1} (0.182)=10.5$ degree. (Answer)

4 0

4 years ago

Use the interactive number line to find -3.2 - 4.

SVEN [57.7K]

Answer:

-7.2

Step-by-step explanation:

Since -3.2 is the first number, this will be the starting point in the number line.

Since we are subtracting, we are going to go 4 units to the left.

-3.2 - 4 = -7.2

Best of Luck!

6 0

3 years ago