How do i solve 7 + x /3 = 2x

Somebody can help me please

sergey [27]

Answer:

sorry but i don't know how...just doing my job

to get 400 points. sorry ;{

Step-by-step explanation:

7 0

3 years ago

Suppose a basketball player has made 223223 out of 406406 free throws. If the player makes the next 22 free throws, I will pay y

makkiz [27]

Answer:

Expected value E = $0.45

Step-by-step explanation:

Expected value E = P×w - P'×l

Where;

P = probability of making the next 2 throw.

P = 223/406 × 223/406 = 0.3017

P' = probability of not making a throw.

P' = 1 - P = 1 - 0.3017

P' = 0.6983

w = expected win = $20

l = Expected loss = $8

Substituting the values;

E = 0.3017 × $20 - 0.6983 × $8

E = $0.4476

Expected value E = $0.45

5 0

4 years ago

2x-<img src="https://tex.z-dn.net/?f=%5Csqrt%7Bx%7D%20x%5E%7B2%7D%20-4x%2B4" id="TexFormula1" title="\sqrt{x} x^{2} -4x+4" alt="

suter [353]

Answer: Spark up Spanish conversations, speak more Spanish, and sound more like a native Spanish speaker with these conversation starters and examples.

Spark up Spanish conversations, speak more Spanish, and sound more like a native Spanish speaker with these conversation starters and examples.

Step-by-step explanation:

3 0

3 years ago

A cylinder is inscribed inside of a square prism so that touches each face of the rectangle or prism. The empty space outside of

siniylev [52]

To solve take (Volume of Prism) - (Volume of Cylinder) = Epoxy

<span>V=(Area of base)(height)
</span>
Both they Cylinder and prism have a height of 40 inches
we can find the sides of the base of the prism by finding the diameter of the cylinder.

C=πd so 84.78 = πd.

Divide both sides by Pi (3.14)
$\frac{84.78}{3.14} = 27$

Half of the diameter is the radius to find the area of the cylinder base. 27/2=13.5

The volume of Prism is found by
$V=l*w*h$

27*27*40 = 29160 sq cm

The volume of cylinder is found by
$V= \pi r^{2}h$

using $3.14* 13.5^{2}*40$ = 22890.6

29160 - 22890.6 = 6269.4 cubic centimeters

6 0

3 years ago

23. A certain type of gasoline is supposed to have a mean octane rating of at least 90. Suppose measurements are taken on of 5 r

Nostrana [21]

Answer:

a) $p_v =P(Z$

b) Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

c) $P(\bar X >90)=1-P(Z$

$1-P(Z$

d) For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

Step-by-step explanation:

Previous concepts and data given

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

We can calculate the sample mean and deviation with the following formulas:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

$\bar X=88.96$ represent the sample mean

$s=1.011$ represent the sample standard deviation

n=5 represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less than 90, the system of hypothesis would be:

Null hypothesis: $\mu \geq 90$

Alternative hypothesis: $\mu < 90$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{88.96-90}{\frac{0.8}{\sqrt{5}}}=-2.907$

Part a

P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=5-1 = 4$

Then since is a left tailed test the p value would be:

$p_v =P(Z$

Part b

Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

Part c

We want this probability:

$P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

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

If we apply this formula to our probability we got this:

$P(\bar X >90)=1-P(Z$

$1-P(Z$

Part d

For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

7 0

3 years ago

How do i solve 7 + x /3 = 2x - 5