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3 years ago

The perimeter of the semicircle is 25.71 cm. Calculate the value of radius x. Take pi to be 3.142

Mathematics

1 answer:

yan [13]3 years ago

5 0

Answer:

5 cm

Step-by-step explanation:

$Perimeter of semicircle = \frac{1}{2} \times 2\pi \: x +2x\\ 25.71 = 3.14 2\times x+ 2x\\ 25.71 = 5.14 2 x\\ x = \frac{25.71}{5.142} \\ x = 5 \: cm$

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3x to the power of 2 - 363 = 0

Vladimir79 [104]

Answer:

yes

Step-by-step explanation:

because it would be 300 so u would be in negative so ya

7 0

3 years ago

Tuan answered 20 customer service calls in 3 hours. At this rate, how many customer service calls can Tuan answer in 7.5 hours?

guapka [62]

First you take the 20 hours it took for the 3 service calls... 20/3=6.67. Then you multiply 6.67X7.5=50.025 hours.

3 0

3 years ago

Do you tailgate the car in front of you? About 35% of all drivers will tailgate before passing, thinking they can make the car i

Vesna [10]

Answer:

(a) The histogram is shown below.

(b) E (X) = 4.2

Step-by-step explanation:

Let X = r = a driver will tailgate the car in front of him before passing.

The probability that a driver will tailgate the car in front of him before passing is, P (X) = p = 0.35.

The sample selected is of size n = 12.

The random variable X follows a Binomial distribution with parameters n = 12 and p = 0.35.

The probability function of a binomial random variable is:

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

(a)

For X = 0 the probability is:

$P(X=0)={12\choose 0}(0.35)^{0}(1-0.35)^{12-0}=0.006$

For X = 1 the probability is:

$P(X=1)={12\choose 1}(0.35)^{1}(1-0.35)^{12-1}=0.037$

For X = 2 the probability is:

$P(X=2)={12\choose 2}(0.35)^{2}(1-0.35)^{12-2}=0.109$

Similarly the remaining probabilities will be computed.

The probability distribution table is shown below.

The histogram is also shown below.

(b)

The expected value of a Binomial distribution is:

$E(X)=np$

The expected number of vehicles out of 12 that will tailgate is:

$E(X)=np=12\times0.35=4.2$

Thus, the expected number of vehicles out of 12 that will tailgate is 4.2.

(c)

The standard deviation of a Binomial distribution is:

$SD(X)=np(1-p)$

The standard deviation of vehicles out of 12 that will tailgate is:

$SD(X)=np(1-p)=12\times0.35\times(1-0.35)=2.73\\$

Thus, the standard deviation of vehicles out of 12 that will tailgate is 2.73.

4 0

3 years ago

Erik correctly rounds three numbers. One and StartFraction 7 over 29 EndFraction rounds to 1 One and five-sixths rounds to 2 0.1

Leya [2.2K]

Answer:

From greatest to least

One and five-sixth rounded to 2

One and StartFraction 7 over 29 rounded to 1

0.16 rounded to 0

Step-by-step explanation:

1+7/29=29+7/29

=36/29

=1.24

Approximately

1+5/6=6+5/6

=11/6

=1.83

Approximately

0.16

Approximately =0

From greatest to least

One and five-sixth rounded to 2

One and StartFraction 7 over 29 rounded to 1

0.16 rounded to 0

7 0

3 years ago

Find an equation for the line that passes through the points (5.-5) and (-4,-2)

ANEK [815]

Answer:

$\large\boxed{y=-\dfrac{1}{3}x-\dfrac{10}{3}\to x+3y=-10}$

Step-by-step explanation:

The slope-intercept form of an equation of a line:

$y=mx+b$

m - slope

b - y-intercept

The formula of a slope:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

We have the points (5, -5) and (-4, -2).

Substiute:

$m=\dfrac{-2-(-5)}{-4-5}=\dfrac{-2+5}{-9}=\dfrac{3}{-9}=-\dfrac{1}{3}$

Put the value of the slope and the coordinates of the point (5, -5) to the equation of a line:

$-5=-\dfrac{1}{3}(5)+b$

$-5=-\dfrac{5}{3}+b$ add 5/3 to both sides

$-\dfrac{15}{3}+\dfrac{5}{3}=b\\\\-\dfrac{10}{3}=b\to b=-\dfrac{10}{3}$

Finally we have the equation of a line in the slope-intercept form:

$y=-\dfrac{1}{3}x-\dfrac{10}{3}$

Convert to the standard form (Ax + By = C):

$y=-\dfrac{1}{3}x-\dfrac{10}{3}$ multiply both sides by 3

$3y=-x-10$ add x to both sides

$x+3y=-10$

4 0

3 years ago