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
nikdorinn [45]
2 years ago
12

A city has 3 new houses for every 7 old houses. If there are 21 new houses in the city, how many old houses are there

Mathematics
1 answer:
yarga [219]2 years ago
5 0

Answer:

A. 49

Step-by-step explanation:

ratio of houses is 3 new to 7 old

21 new is 7 times more than 3, so 7 will also be 7 times more

so, 21 to 49

I hope that made sense

You might be interested in
A horticulturist working for a large plant nursery is conducting experiments on the growth rate of a new shrub. Based on previou
valkas [14]

Answer:

t=\frac{1.8-2}{\frac{0.5}{\sqrt{48}}}=-2.771    

The degrees of freedom are given by:

df=n-1=48-1=47  

And the p value would be:

p_v =P(t_{(47)}    

Since the p value is lower than the significance level we have enough evidence to conclude that the true mean for this case for the growth rate is less than 2cm per week

Step-by-step explanation:

Information given

\bar X=1.8 represent the sample mean for the growth

s=0.5 represent the sample standard deviation    

n=48 sample size    

\mu_o =2 represent the value that we want to compare

\alpha=0.01 represent the significance level

t would represent the statistic    

p_v represent the p value

System of hypothesis

We need to conduct a hypothesis in order to check if the true mean is less than 2cm per week, the system of hypothesis are :    

Null hypothesis:\mu \geq 2    

Alternative hypothesis:\mu < 2    

Since we don't know the population deviation the statistic is given by:

t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}} (1)    

Replacing the info given we got:

t=\frac{1.8-2}{\frac{0.5}{\sqrt{48}}}=-2.771    

The degrees of freedom are given by:

df=n-1=48-1=47  

And the p value would be:

p_v =P(t_{(47)}    

Since the p value is lower than the significance level we have enough evidence to conclude that the true mean for this case for the growth rate is less than 2cm per week

6 0
3 years ago
A mountain climber ascended
crimeas [40]
Coool veryyy coool omg wow
5 0
3 years ago
A family has an annual income of ​$30,600 Of​ this, 1/4 is spent for​ food, 1/5 for​ housing, 1/10 for​ clothing, 1/9 for​ savin
Ksenya-84 [330]

Answer:

$6,120

Step-by-step explanation:

1/5 (one-fifth) of the family's annual income ($30,600) is spent on housing- as the word problem states.

You have to find 1/5 (one-fifth) of* $30,600.

Write it out as an equation.

\frac{1}{5}  \times 30600

*The <em>of</em><em> </em>in the word equation (1/5 of 30600) simply means multiplication.

4 0
3 years ago
Find the area of the trapezoid below in square centimeters (cm). The area of the trapezoid is
BARSIC [14]

Answer:

122.5

Step-by-step explanation:

Use the area formula for a trapezoid (attached below as an image):

A = area in sq cm

a = top base

b = bottom base

h = height

Correspond the correct values with the variables:

a = 14

b = 21

h = 7

A = 1/2 * (14 + 21) * 7

A = 1/2*(35)*7

A = 17.5 * 7

A = 122.5 sq cm

Hope this helps (●'◡'●)

6 0
3 years ago
Plz help I had no idea these things even existed...
GrogVix [38]
X/12=(2 1/3)/5  note that 2 1/3=7/3

x/12=(7/3)/5

x/12=7/15  multiply both sides by 12

x=84/15

x=28/5

x=56/10

x=5.6
4 0
3 years ago
Other questions:
  • 9. If a car travels 65 kilometers in 25 minutes, what is its speed in miles per hour? (1.6 km = 1 mile)
    15·1 answer
  • How do I solve this
    6·1 answer
  • If y=3x+1 were changed to y=x+1 how would the graph of the new function compare with the original?
    13·1 answer
  • Factor out the coefficient of the variable term The expression 1/10k-7/10 factored is
    6·1 answer
  • Can you help me with this problem
    6·2 answers
  • HELP NEED ASAP FOR TOMORROW ITS FOR MY HOMEWORK!! ILL MARK BRAINLIEST IF RIGHT!!​
    6·1 answer
  • A boat drops an anchor 17.5 feet to the bottom of a lake.If the anchor falls at a rate of .07 feet each second how long will it
    13·1 answer
  • Multi-Step Max's school bought boxes of
    7·1 answer
  • How many solutions does the equation 6a - 3a - 6 = 2 + 3 have?
    10·1 answer
  • What is the answer of this on (if 3 pieces of candy cost $2.10 how much would four pieces cost)
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!