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
mylen [45]
2 years ago
15

Use a number line to add or subtract. 3−(-1)=

Mathematics
1 answer:
Bogdan [553]2 years ago
8 0

Answer:

4

Step-by-step explanation:

rule 1 positive + positive= positive

rule 2 negative plus negative = negative

You might be interested in
the perimeter of a field has a perimeter of 270 feet and the length is 35 feet longer than the width. Write and graph the system
Stells [14]

Answer:

So I don't know the equation but I know the answer.

Length: 170 ft.

Width: 100 ft.

Step-by-step explanation:

The perimeter (The length all around) is 270. You do the perimeter divided by two and add 35, because we know they are almost equal except for one side is 35 ft. longer, That is your length. You the take the perimeter minus the length to get the width.

Equationish: P÷2= x+35= y -> P-y=w

Or: 270÷2= 135+35=170 -> 270-170= 100ft.

8 0
3 years ago
A farmer randomly inspected 16 of his 93 peach trees for signs of disease. Two of those trees showed signs of disease. Find .
Dmitriy789 [7]
 <span>I think you wanted to find p̂, or "p-hat". This is simply the proportion of the sample. So: 

p̂ = 16/93 ~= 0.172 

Hope this helps :)</span>
4 0
3 years ago
Read 2 more answers
Which situation best represents a linear function?
yanalaym [24]

Answer:

A

Step-by-step explanation:

y=3x+55

5 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
Please help :) I’m really in need of assistance and would appreciate it.
BaLLatris [955]

Answer:

D) 0.5x^3y + 4x^2 y^2 - 2xy^3

Step-by-step explanation:

Set up an equation to model the situation,

(-0.5xy)(x^2 + 8xy - 4y^2)

Distribute, multiply each term in the parenthesis with the term outside of the parenthesis. Don't forget the laws of exponents, when one multiplies two exponents, with the same base, then one adds the two exponents. A number with no exponential term is two the first degree meaning that it is to the power of one.

-0.5x^3 y - 4x^2 y^2 + 2xy^3

4 0
3 years ago
Other questions:
  • 25 penalties decreased by 32%?
    8·1 answer
  • Which property is shown in the following statement? 7 · 1 = 7 A. identity property of multiplication B. associative property of
    13·2 answers
  • Is a y value a point, a horizontal line, a vertical line, or none of these? Explain your thinking.
    6·2 answers
  • What ordered pair is a solution to the equation y=-3x-5
    14·1 answer
  • Find 4y2 + y, where y = 3 Select the best answer from the choices provided.
    7·2 answers
  • A 10-foot ladder leans against a wall with its foot braced 3 feet from wall’s base. How far up the wall does the ladder reach? S
    5·2 answers
  • A truck driver drove 48 miles in 45 minutes.At this rate,how many miles can the truck drive in one hour?
    11·2 answers
  • On a certain hot​ summer's day, 459 people used the public swimming pool. The daily prices are $1.50 for children and $2.00 for
    7·1 answer
  • HAPPY BIRTHDAY TINA♡◇♡◇♤♧♡◇◇♡♡
    6·2 answers
  • Is y=2^x linear, exponential or neither
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!