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3 years ago

The sum of twice a number and 18 less than the number is the same as the difference between -30 and the number

Mathematics

2 answers:

maksim [4K]3 years ago

6 0

2x + x - 18 = -30 - x

Monica [59]3 years ago

6 0

Lets say the number is x. The formula would be:
2x + x - 18 = x -30
To find x, you have to get rid of everything els, so minus x from both sides.
2x - 18 = -30
Since -30 is the smallest number, you get rid of that next. Add 30 to both sides
2x + 12 = 0
Now get rid of +12 by doing -12.
2x = -12
divide both sides by 2 to get x by itself
x = -6.

To double check your answer, do the reverse. Substitute -6 iinto the equation wherever it says x.

2x + x - 18 = x -30 becomes (2 x -6) + (-6 - 18) = -6 - 30.
Use BIDMAS (Brackets Indices Division Multiplication Addition Subtraction) to get your answer. Brackets are first
-12 + -24 = -6 - 30
-36 = -6 - 30 which is basically -36 = -36

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A drug company is considering marketing a new local anesthetic. The effective time of the anesthetic the drug company is current

lapo4ka [179]

Using the z-distribution, we have that:

The hypothesis test is:

$H_0: \mu = 7.4$

$H_1: \mu < 7.4$

The p-value is of 0.0668.

The critical value is $z^{\ast} = -1.28$

b) Since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.

Item a:

At the null hypothesis, it is tested if the mean is of 7.4 minutes, that is:

$H_0: \mu = 7.4$

At the alternative hypothesis, it is tested if the mean is lower than 7.4 minutes, that is:

$H_1: \mu < 7.4$

We have the standard deviation for the population, hence, the z-distribution is used.

The test statistic is given by:

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

The parameters are:

$\overline{x}$ is the sample mean.

$\mu$ is the value tested at the null hypothesis.

$\sigma$ is the standard deviation of the sample.

n is the sample size.

For this problem, the values of the parameters are: $\overline{x} = 7.1, \mu = 7.4, \sigma = 1.2, n = 36$ .

Hence, the value of the test statistic is:

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

$z = \frac{7.1 - 7.4}{\frac{1.2}{\sqrt{36}}}$

$z = -1.5$

Using a z-distribution calculator, the p-value is of 0.0668.

Also using a calculator, considering a left-tailed test, as we are testing if the mean is less than a value, the critical value with a significance level of 0.1 is of $z^{\ast} = -1.28$ .

Item b:

Since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.

You can learn more about the use of the z-distribution to test an hypothesis at brainly.com/question/16313918

5 0

1 year ago

Can please cross multiply this for me :)

Alchen [17]

64 x 100 = 6400
11 x x = 11x
I’ll solve this out for you
11x = 6400
Divide 11 from both sides
x = 581.8
Hope this helps!

4 0

3 years ago

Read 2 more answers

Udrey used compensation to mentally solve the subtraction problem 5.35−0.07

Licemer1 [7]

The last step you need to do is 5.25+0.03, because you took away 0.03 more than what the question asked so you need to add the 0.03 back, which gets you the final result of 5.28.

6 0

3 years ago

Debora [2.8K]

Answer:

the side of a square is 45 m

Step-by-step explanation:

The computation of the side of the square field that contains the similar area as compared with rhombus is given below:

As we know that

Area of rhombus = Base × Altitude

= 81 × 25

= 2025

And, area of Square = Side × side

2025 = side^2

side = √2025

= 45m

Hence, the side of a square is 45 m

8 0

2 years ago

What is the slope of the line that passes through the points(7,-9) and (15,-29)?

Alex Ar [27]

(Y-Y1)/(X-X1)
(-9-(-29))/(7-15)
20/-8
-2 1/2
The slope is -2 1/2

3 0

2 years ago