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
andreev551 [17]
3 years ago
11

A new crew of painters can paint a small apartment in 12 hours. an experienced crew can paint the small apartment in 6 hours. ho

w many hours does it take to paint the apartment when the two crews work together?
Mathematics
1 answer:
Yakvenalex [24]3 years ago
6 0
This is the concept of proportionality, we are required to calculate for the number of hours two crews can use to paint the house altogether.
Here proceed as follows;
number of hours new crew can paint=12 hrs
portion of work painted by new crew in 1 hour= 1/12

number of hours experienced crew can paint=6 hours
Portion of work painted by experienced crew in 1 hour=1/6

Portion of work painted by the two crews altogether in 1 hour will be:
1/6+1/12=1/4

thus the total amount of hours that the two painters will take to paint will be:
4 hours


You might be interested in
Plz help me !!!!!!!!!!!!!
Digiron [165]

Answer:

It's D ...

hope it helps

5 0
2 years ago
Read 2 more answers
Please help me quickly
hichkok12 [17]

Answer:

Convenience sampling

Step-by-step explanation:

5 0
3 years ago
PLEASE HELP ME I BEG I WILL GIVE BRAINLIEST
ohaa [14]

Answer:

Mean = (2.2 + 2.4 + 2.5 + 2.5 + 2.6 + 2.7)/6 = 2.48

Standard deviation = √(summation(x - mean)²/n

n = 6

Summation(x - mean)² = (2.2 - 2.48)^2 + (2.4 - 2.48)^2 + (2.5 - 2.48)^2 + (2.5 - 2.48)^2 + (2.6 - 2.48)^2 + (2.7 - 2.48)^2 = 0.1484

Standard deviation = √(0.1484/6

s = 0.16

Standard error = s/√n = 0.16/√6 = 0.065

Part B

Confidence interval is written as sample mean ± margin of error

Margin of error = z × s/√n

Since sample size is small and population standard deviation is unknown, z for 98% confidence level would be the t score from the student t distribution table. Degree of freedom = n - 1 = 6 - 1 = 5

Therefore, z = 3.365

Margin of error = 3.365 × 0.16/√6 = 0.22

Confidence interval is 2.48 ± 0.22

Part C

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

H0: µ = 2.3

For the alternative hypothesis,

H1: µ > 2.3

This is a right tailed test

Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 6

Degrees of freedom, df = n - 1 = 6 - 1 = 5

t = (x - µ)/(s/√n)

Where

x = sample mean = 2.48

µ = population mean = 2.3

s = samples standard deviation = 0.16

t = (2.48 - 2.3)/(0.16/√6) = 2.76

We would determine the p value using the t test calculator. It becomes

p = 0.02

Assuming significance level, alpha = 0.05.

Since alpha, 0.05 > than the p value, 0.02, then we would reject the null hypothesis. Therefore, At a 5% level of significance, the sample data showed significant evidence that the mean absolute refractory period for all mice when subjected to the same treatment increased.

Step-by-step explanation:

7 0
2 years ago
An interest-free period during which a credit card owner can pay off a balance
uysha [10]
....................
7 0
2 years ago
Please hlp me with this question <br>15 POINTS​
Gala2k [10]

Answer:

1/13, 12/13

Step-by-step explanation:

There are 4 aces in a 52 card deck so P(Ace) = 4 / 52 = 1 / 13.

There are 52 - 4 = 48 cards that are not aces out of the whole 52 cards in the deck so P(not Ace) = 48 / 52 = 12 / 13.

5 0
3 years ago
Other questions:
  • Find cos B.<br><br> A. 41/40<br> B. 9/41<br> C. 40/41<br> D. 9/40
    13·2 answers
  • An asteroid follows a hyperbolic path defined by the equation 16x2 − 9y2 = 576. If one of its foci is the sun's position, the mi
    5·1 answer
  • Simplify (8z - 10) ÷ (-2) + 5(z - 1).       plz show work 
    8·1 answer
  • Which of the following is the graph of y=√-x-3<br><br> Please help!!
    5·1 answer
  • HELP ME GEOMETRY PLZZZZZZZZ solve for SR
    6·1 answer
  • Determine which postulate or theorem can be used to prove that
    5·1 answer
  • For what value of a does the equation ax^2−3x−5=0 have 1 as one of its roots?
    10·1 answer
  • --17 -(-17.9)<br> What is the work?
    10·2 answers
  • What is the notation for an inverse function?
    10·2 answers
  • A food truck did a daily survey of customers to find their food preferences. the data is partially entered in the frequency tabl
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!