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steposvetlana [31]

3 years ago

15

there are 90 chairs arranged for people to watch a band concert. if 75 chairs have people in them during the concert, what perce

ntage of the chairs are fiilled

1 answer:

sleet_krkn [62]3 years ago

5 0

Answer: 83.3%

Step-by-step explanation:

Simply you want to divide 75 by 90 and you will get 83.3%

You might be interested in

Suppose the expected tensile strength of type-A steel is 103 ksi and the standard deviation of tensile strength is 7 ksi. For ty

ExtremeBDS [4]

Answer:

a

i So the approximate distribution of $\= X$ is $\mu_{\= X} =103$ and $\sigma_{\= X} = 0.783$

ii So the approximate distribution of $\= Y$ is $\mu_{\= Y} =105$ and $\sigma_{\= Y} = 0.645$

b

the approximate distribution of $\=X - \= Y$ is $E (\= X - \= Y) = -2$ and $\sigma_{\= X - \=Y}=1.029$

Here we can see that the mean of the approximate distribution is negative which tell us that this negative value of the data for $\=X - \= Y$ sample are more and their frequency occurrence is higher than the positive values

c

the value of $P(-1 \le \=X - \= Y \le 1)$ is $= -0.1639$

Step-by-step explanation:

From the question we are given that

The expected tensile strength of the type A steel is $\mu_A = 103 ksi$

The standard deviation of type A steel is $\sigma_A = 7ksi$

The expected tensile strength of the type B steel is $\mu_B = 105\ ksi$

The standard deviation of type B steel is $\sigma_B = 5 \ ksi$

Also the assumptions are

Let $\= X$ be the sample average tensile strength of a random sample of 80 type-A specimens

Here $n_a =80$

Let $\= Y$ be the sample average tensile strength of a random sample of 60 type-B specimens.

Here $n_b = 60$

Let the sampling distribution of the mean be

$\mu _ {\= X} = \mu$

$=103$

Let the sampling distribution of the standard deviation be

$\sigma _{\= X} = \frac{\sigma }{\sqrt{n_a} }$

$= \frac{7}{\sqrt{80} }$

$=0.783$

So What this mean is that the approximate distribution of $\= X$ is $\mu_{\= X} =103$ and $\sigma_{\= X} = 0.783$

For $\= Y$

The sampling distribution of the sample mean is

$\mu_{\= Y} = \mu$

$= 105$

The sampling distribution of the standard deviation is

$\sigma _{\= Y} = \frac{\sigma }{\sqrt{n_b} }$

$= \frac{5}{\sqrt{60} }$

$= 0.645$

So What this mean is that the approximate distribution of $\= Y$ is $\mu_{\= Y} =105$ and $\sigma_{\= Y} = 0.645$

Now to obtain the approximate distribution for $\=X - \= Y$

$E (\= X - \= Y) = E (\= X) - E(\= Y)$

$= \mu_{\= X} - \mu_{\= Y}$

$= 103 -105$

$= -2$

The standard deviation of $\=X - \= Y$ is

$\sigma_{\= X - \=Y} = \sqrt{\sigma_{\= X}^2 - \sigma_{\= Y}^2}$

$= \sqrt{(0.783)^2 + (0.645)^2}$

$=1.029$

Now to find the value of $P(-1 \le \=X - \= Y \le 1)$

Let us assume that $F = \= X - \= Y$

$P(-1 \le F \le 1)$ $= P [\frac{-1 -E (F)}{\sigma_F} \le Z \le \frac{1-E(F)}{\sigma_F} ]$

$= P[\frac{-1-(-2)}{1.029} \le Z \le \frac{1-(-2)}{1.029} ]$

$= P[0.972 \le Z \le 2.95]$

$= P(Z \le 0.972) - P(Z \le 2.95)$

Using the z-table to obtain their z-score

$= 0.8345 - 0.9984$

$= -0.1639$

3 0

2 years ago

How do I workout/find the unknown angles please

Cerrena [4.2K]

Answer: x = 135 degrees and y = 225 degrees.

Step-by-step explanation: To solve this problem we first use the equation (n-2)*180 [n being the number of sides] to find the sum of interior angles in the figure. We plug the values in: (8-2)*180 = 6*180 degrees = 1080 degrees. We divide this by 8 to get the measure of an interior angle: 1080 degrees/8 = 135 degrees. Since all the interior angles of a regular polygon are congruent, we can say that angle x + angle y = 360 degrees. Thus subtract x degrees from 360 degrees to get y: 360 degrees - 135 degrees = 225 degrees. Therefore, x = 135 degrees and y = 225 degrees.

6 0

2 years ago

The amount of snowfall falling in a certain mountain range is normally distributed with a mean of 70 inches and a standard devia

Sav [38]

Answer:

The probabilty would be 87.34%

Step-by-step explanation:

Add all the numbers together and multiply them as a percetnage by four

6 0

3 years ago

Triangle A'B'C' is the image of triangle ABC under a rotation about point Q.<br><br>

yan [13]

9514 1404 393

Answer:

True; about 120° CCW rotation about Q

Step-by-step explanation:

Triangle A'B'C' appears to be congruent to triangle ABC and about the same distance from point Q. The angle of rotation from ABC to A'B'C' appears to be about 120° counterclockwise when measured using a geometry program.

Triangle A'B'C' is the image of triangle ABC under rotation about 120° CCW about point Q.

_____

<em>Additional comment</em>

If choices of rotation angle are ±135° or ±165°, the best choice would be ...

135°

3 0

2 years ago

El constante de 2× +1

andre [41]

The answer is positive 2

4 0

3 years ago