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Over [174]
2 years ago
6

PLEASE HELP I JUST NEED TO KNOW HOW TO DO IT

Mathematics
2 answers:
RoseWind [281]2 years ago
7 0
Your answer should be x=7 and y=7
Brilliant_brown [7]2 years ago
5 0

Answer:

y=7, x=7

Step-by-step explanation:

They both equal y, so you can set the right part of the equations equal to each other

4x-21=2x-7

solve for x

2x-21=-7

2x=14

x=7

knowing x, we can now substitute back into one of the original equations to find y

y=4(7)-21=28-21=7

or

y=2(7)-7=14-7=7

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A theory predicts that the mean age of stars within a particular type of star cluster is 3.3 billion years, with a standard devi
Luden [163]

Answer:

Null hypothesis:\mu \leq 3.3  

Alternative hypothesis:\mu > 3.3  

z=\frac{3.4-3.3}{\frac{0.4}{\sqrt{50}}}=1.768  

Since is a one right tailed test the p value would be:  

p_v =P(z>1.768)=0.039  

Step-by-step explanation:

Data given and notation

\bar X=3.4 represent the sample mean  

\sigma=0.4 represent the population deviation for the sample

n=50 sample size  

\mu_o =3.3 represent the value that we want to test  

\alpha represent the significance level for the hypothesis test.  

t would represent the statistic (variable of interest)  

p_v represent the p value for the test (variable of interest)  

State the null and alternative hypotheses to be tested  

We need to conduct a hypothesis in order to determine if the mean is higher than 3.3, the system of hypothesis would be:  

Null hypothesis:\mu \leq 3.3  

Alternative hypothesis:\mu > 3.3  

Compute the test statistic  

We know the population deviation, so for this case is better apply a z 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".  

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

z=\frac{3.4-3.3}{\frac{0.4}{\sqrt{50}}}=1.768  

P value

Since is a one right tailed test the p value would be:  

p_v =P(z>1.768)=0.039  

6 0
3 years ago
Given that MQL =180° and XQR = 180°, which equation could be used to solve problems involving the relationships
Ganezh [65]

Answer:

Option A is the right answer.

146-4b = 122-1b

Reason: vertical angles

8 0
2 years ago
Which which division problem does the diagram below best illustrate?<br><br><br>60 points ​
siniylev [52]

Answer:

Step-by-step explanation:

32 divide 4 = 8

4 0
3 years ago
Read 2 more answers
Write the umber 10.5 in the form a/b
Dafna11 [192]
The umber  10.5  can be written as

==>  21 / 2

==>  42 / 4

==>  63 / 6

==>  84 / 8

==>  105 / 10

and many, many other ways.

They ALL have the same value.

3 0
3 years ago
Read 2 more answers
4x-5=x-1+3x I need help
labwork [276]

Answer:

x = no solutions

General Formulas and Concepts:

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

  1. Brackets
  2. Parenthesis
  3. Exponents
  4. Multiplication
  5. Division
  6. Addition
  7. Subtraction
  • Left to Right

Equality Properties

Step-by-step explanation:

<u>Step 1: Define equation</u>

4x - 5 = x - 1 + 3x

<u>Step 2: Solve for </u><em><u>x</u></em>

  1. Combine like terms:                    4x - 5 = 4x - 1
  2. Subtract 4x on both sides:          -5 ≠ -1

Here we see that -5 does not equal -1.

∴ This equation has no solutions.

8 0
2 years ago
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