1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
RSB [31]
2 years ago
10

Solve 15/4 -7 X=9 answer the question​

Mathematics
1 answer:
Svet_ta [14]2 years ago
8 0

\frac{15}{4}  - 7x = 9 \\  \\   \frac{15}{4}  - 9 = 7x \\  \\ 7x =  \frac{15 - 36}{4}  \\  \\ 7x =  \frac{ - 21}{4}  \\  \\ x =  \frac{ - 21}{4 \times 7}  \\  \\ x =  \frac{ - 3}{4} .

You might be interested in
8 is 40% of what number? Please show your work
KengaRu [80]
Do a proportion
40/100= 8/x
8 x 100= 800
Cross multiply and divide
800 divided by 40= 20
So answer is 20
5 0
3 years ago
Read 2 more answers
12x + 10x what is the awnser
KIM [24]

Answer:

22x?

Step-by-step explanation:

is there more to this question? if not its just simple addition and then add "x" at the end

7 0
2 years ago
What is the equation of the line<br> with the points (1, 4) and (5, 12)?<br> 12
DerKrebs [107]

Answer:

y = 2x + 2

Hope you have a great day!

7 0
3 years ago
Calcium is essential to tree growth because it promotes the formation of wood and maintains cell walls. In 2010, the concentrati
sergij07 [2.7K]

Answer:

The p-value obtained from the hypothesis test is greater than the significance level at which the test was performed, hence, we fail to reject the null hypothesis & say that there isn't enough evidence from the sample to conclude that the the calcium concentrations have changed since 2010.

Step-by-step explanation:

To perform this test, we need to first obtain the sample mean and sample standard deviation.

The data is 0.065 0.087 0.070 0.262 0.126 0.183 0.120 0.234 0.313 0.108

Mean = (sum of variables)/(sample size)

= (0.065+0.087+0.070+0.262+0.126+0.183+0.120+0.234+0.313+0.108)/10

= 0.1568 milligram per liter

Standard deviation = σ = √[Σ(x - xbar)²/N]

Σ(x - xbar)² = 0.00842724+0.00487204+0.00753424+0.01106704+0.00094864+0.00068644+0.00135424+0.00595984+0.02439844+0.00238144

= 0.0676296

σ = √[Σ(x - xbar)²/N] = √(0.0676296/10) = 0.08224 milligrams per liter

To do an hypothesis test, we need to first define the null and alternative hypothesis

The null hypothesis plays the devil's advocate and usually takes the form of the opposite of the theory to be tested. It usually contains the signs =, ≤ and ≥ depending on the directions of the test.

While, the alternative hypothesis usually confirms the the theory being tested by the experimental setup. It usually contains the signs ≠, < and > depending on the directions of the test.

For this question, the null hypothesis would be that there is no significant evidence to suggest that the the calcium concentrations have changed since 2010. That is, the calcium concentrations haven't changed since 2010.

The alternative hypothesis is that there is significant evidence to suggest that the the calcium concentrations have changed since 2010. That is, the calcium concentrations haven't changed since 2010.

Mathematically,

The null hypothesis is represented as

H₀: μ = 0.11 milligrams per liter

The alternative hypothesis is given as

Hₐ: μ ≠ 0.11 milligrams per liter

To do this test, we will use the t-distribution because no information on the population standard deviation is known

So, we compute the t-test statistic

t = (x - μ₀)/σₓ

x = sample mean = 0.1568 milligram per liter

μ₀ = the mean calcium concentrations from 2010 = 0.11 milligrams per liter

σₓ = standard error = (σ/√n)

where n = Sample size = 10

σ = Sample standard deviation = 0.08224 milligrams per liter

σₓ = (σ/√n) = (0.08224/√10) = 0.026

t = (0.1568 - 0.11) ÷ 0.026

t = 1.80

checking the tables for the p-value of this t-statistic

Degree of freedom = df = 10 - 1 = 10 - 1 = 9

Significance level = 0.05

The hypothesis test uses a two-tailed condition because we're testing in two directions. (Greater than and less than)

p-value (for t = 1.80, at 0.05 significance level, df = 9, with a two tailed condition) = 0.105391

The interpretation of p-values is that

When the (p-value > significance level), we fail to reject the null hypothesis and when the (p-value < significance level), we reject the null hypothesis and accept the alternative hypothesis.

So, for this question, significance level = 0.05

p-value = 0.105391

0.105391 > 0.05

Hence,

p-value > significance level

This means that we fail to reject the null hypothesis & say that there isn't enough evidence to conclude that the the calcium concentrations have changed since 2010.

Hope this Helps!!!

8 0
3 years ago
A number, y, is five times another number, x. The sum of the two numbers is 42. Write the system of equations.
vovikov84 [41]

Answer:

5x+x=42

6x=42

x=7

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
Other questions:
  • A van will drive ten miles north, 15 miles south, and then five miles north again. The van gets 33 miles per gallon, and there i
    14·2 answers
  • In a triangle whose perimeter is 44 centimeters, the length of the longest side is 4 cm less than the sum of the lengths of the
    8·2 answers
  • Vanessa invested 2500 into an account that will increase in value by 3.5% each year. Find the value of the investment after 20 y
    10·2 answers
  • The tires on your bicycle have a radius of 14 inches. How many rotations does each tire make when you travel 900 feet? Round you
    6·1 answer
  • One important test for kidney disease involves measuring the levels of bicarbonate (HCO−3) in blood. Normal bicarbonate levels f
    6·1 answer
  • One person can do a certain job in twenty-one minutes, and another person can do the same job in twenty-eight minutes. How many
    7·2 answers
  • an item on sale costs 30% of the original price If the original price was $50 what is the sales price ​
    14·2 answers
  • How do you write 0.16 repeating as a fraction
    9·2 answers
  • What is the image of -8 ,8 after a dilation by a scale factor of one fourth centered at the origin?
    13·1 answer
  • The measure of A∠ is greater than twice the measure of B∠ . If the angles’ sum is 42 degrees, find the measure of A∠ .
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!