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
muminat
3 years ago
7

Provide an appropriate response. In order to efficiently bid on a contract, a contractor wants to be 95% confident that his erro

r is less than two hours in estimating the average time it takes to install tile flooring. Previous contracts indicate that the standard deviation is 4.5 hours. How large a sample must be selected?
a.19
b.4
c.5
d.20
Mathematics
1 answer:
lidiya [134]3 years ago
5 0

Answer:

d. 20

Step-by-step explanation:

Standard deviation is 4.5

Margin error for the problem is 2 hours

Probability 95%, that means that the siginficance level α is 1 – p

α = 1 – 0.95 = 0.05

margin of error (ME) can be defined as follows

ME = Z(α/2) * standard deviation/ √n

Where n is the sample size

Z(0.05/2) = Z(0.025)

Using a z table Z = 1.96

Now, replacing in the equation and find n

2 = 1.96 * 4.5/ √n

2 = 8.82/√n

√n = 8.82/2

√n = 4.41

n = 4.41^2

n = 19.44 ≈ 20

You might be interested in
Which equation represents "the product of a number and 24 is 72"?
Nataly [62]

Answer:

Step-by-step explanation:

24 p=72

5 0
3 years ago
Read 2 more answers
What is 8 thousands 15 hundreds 15 Tens 18 ones written in standard form ?
ryzh [129]
I'm not sure what you are trying to convey, but you cannot have more than one digit, so this is imposible
8 0
3 years ago
Read 2 more answers
Dilations… please help I will give you brainless
DochEvi [55]

Answer:

The scale factor is 0.5

Step-by-step explanation:

Divide.

2/1=2

4/2=2

4/2=2

8/4=2

2/1=2

5/1.25=2

Now then, since this is a shrinking factor, divide 1 by the common outcome from the last section (2) to get 0.5

4 0
3 years ago
Riley finished her 5k race in One-half hour. Darby finished the same race in Three-fifths hour. Which statement explains which g
Andrej [43]

Answer:

Riley did better than Darby because One-half < Three-fifths.

Step-by-step explanation:

The statement that explains which girl did better would be that

Riley did better than Darby because One-half < Three-fifths.

There are a total of 60 minutes in an hour, If we multiply each of these fractions by 60 minutes it would give us the exact number of minutes that each girl took to finish the race.

Riley: \frac{1}{2} * 60 = 30 minutes

Darby: \frac{3}{5} * 60 = 36 minutes

Therefore, we can see that it took Riley 6 minutes less than Darby to finish the race meaning that she had the better result.

3 0
3 years ago
Read 2 more answers
What is m∠G ?<br><br> Enter your answer in the box.
Elena-2011 [213]
We are given all the angle measures, therefore we can equate all the expressions to 180 degrees. We can do this by using the Triangle Angle Sum Theorem, which states that all triangles' interior angles add up to 180 degrees. After we do that, we get:
x + 3x + 25 + x - 5 = 180
Now, just solve for x:
x + 3x + 25 + x - 5 = 180
5x + 20 = 180
5x = 160
x = 32
We've found the value of x, but the question asks us the measure of angle G. We can find the angle measure by substituting 32 into the expression for angle G. Doing so and simplifying gives us 121 degrees. Therefore, the measure of angle G is 121 degrees. Hope my answer has come of aid to you and have a great day!
6 0
3 years ago
Read 2 more answers
Other questions:
  • How long is 1 million days ago in hours in scientific notationHow long was Amelia days ago and I was in scientific notation
    12·1 answer
  • 67cd
    12·2 answers
  • Help! I need help please
    13·2 answers
  • 5(4n - 11) - 3n + 20 and 17n - 35 are equivalent expressions.(true or false)please exlplain with FULL SENTANCES
    14·2 answers
  • Someone help me with this please
    15·2 answers
  • How do you write 0.0000248 in scientific notation?
    10·2 answers
  • What is the answer to d-2=8+6
    8·2 answers
  • Check if the point (-3, -5) lies on the line y= 2x -1 <br><br><br> Plzzzzz hurry
    6·1 answer
  • Write the equation of the line that passes through the points (9, -1) and (-6, -3).
    12·1 answer
  • Where would the line go??? Please help asap!!
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!