For which equation would x=5 be a solution?

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

3 years ago

3(x+2)^2=48 with word steps

lesya692 [45]

Answer:

Divide both sides by 3.

(x+2)^2=16

Square root both sides.

x+2= ± 4 (plus OR minus, can be either so we have to include both)

Minus 2 from both sides.

x=-2 ± 4

Add and minus the 4 to -2.

x = -2-4 = -6 and x=-2+4 = 2

8 0

3 years ago

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PLEASE HELP ASAP ASAP URGENT WILL GIVE BRAINLIEST

Luden [163]

Answer:

for the solve and check:

$2\frac{3}{8}+x=3\frac{1}{4} \\2\frac{3}{8}-2\frac{3}{8}+x=3\frac{1}{4}-2\frac{3}{8}\\\\x=3\frac{1}{4}-2\frac{3}{8}\\\\\\x=\frac{7}{8}$

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

$3\frac{3}{8}+x=4\frac{1}{4} \\3\frac{3}{8}-3\frac{3}{8}+x=4\frac{1}{4}-3\frac{3}{8}\\\\x=4\frac{1}{4}-3\frac{3}{8}\\\\\\x=\frac{7}{8}$

for the second solve and check:

$4\frac{3}{8}+x=5\frac{1}{4} \\4\frac{3}{8}-4\frac{3}{8}+x=5\frac{1}{4}-4\frac{3}{8}\\\\x=5\frac{1}{4}-4\frac{3}{8}\\\\\\x=\frac{7}{8}$

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

$5\frac{3}{8}+x=6\frac{1}{4} \\5\frac{3}{8}-5\frac{3}{8}+x=6\frac{1}{4}-5\frac{3}{8}\\\\x=6\frac{1}{4}-5\frac{3}{8}\\\\\\x=\frac{7}{8}$

8 0

2 years ago

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Write the equation of a vertical line that passes through the point (–4, 4).

FinnZ [79.3K]

The question asks for a vertical line, and if it is vertical, it cannot be y = ... because that is horizontal. We also know it passes through the x-coordinate of -4, so the answer is x = -4.

4 0

3 years ago

Can somebody please help...I don’t understand it would mean a lot ❤️

ohaa [14]

Answer:

y=0.5x+8

Step-by-step explanation:

Use the formula for the equation of a line y=mx+c where m is the slope and c is a number.

To find the slope, take two points (x₁,y₁) (x₂,y₂) and put them into the slope equation m=(y₂-y₁)/(x₂-x₁):

We can take two points from the graph: (2,9) (4,10)

m=(y₂-y₁)/(x₂-x₁)

m=(10-9)/(4-2)

m=1/2 or 0.5

Now sub this value in for m and our formula looks like this:

y=0.5x+c

To find the value of c, sub in one of the points, eg. (4,10)

y=0.5x+c

10=0.5(4)+c

10=2+c

c=8

So now that we now m and c, our equation is complete :D

y=0.5x+8

4 0

2 years ago

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