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
2 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]2 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
Using the number line, determine which expressions have a value that is greater than –8. Select Yes or No for each expression. l
Nimfa-mama [501]
<h3>Answer:</h3>

yes

  • -6-(-6)
  • -4-(-7)

no

  • all others
<h3>Step-by-step explanation:</h3>

Doing what the directions say is generally a good idea.

Adding a number moves to the right; subtracting a number moves to the left. Subtracting a negative number is the same as adding its opposite.

The arrowhead end of the line in the figure is the end result. Two of them end up to the right of -8, that is, greater than -8.

8 0
3 years ago
Read 2 more answers
The numerator of a fraction is 6. Which of the following could be the denominator of the fraction so that it is already in lowes
bogdanovich [222]

Answer:

19, because it wouldn't be close to becoming a whole.

Step-by-step explanation:

8 0
2 years ago
7a-5b+4<br> a=2, b=3 and c=-6
KengaRu [80]

Answer: 3

Step-by-step explanation:

the statement given us:

7a-5b+4

a= 2

b= 3

so we have:

7*(2)-5*(3)+4

14-15+4 = 3

the answer is 3

6 0
3 years ago
Kristi is the food manager of a summer camp. Each day, the kids at the camp get a choice of a pizza, chicken nuggets, fish, or s
Ad libitum [116K]

Answer:

Kristi's prediction is not valid. The probability of a kid choosing a fish plate is about 21%.

Step-by-step explanation:

I took the test ✌

8 0
3 years ago
9) The list price of a car is $12,600.00. Liza gets a 12% discount on the list price. How much does she need to pay for the car?
o-na [289]

Answer:

11,088

Step-by-step explanation:

12,600.00*(1-0.12)=11088

1-0.12 is the reduction

8 0
2 years ago
Other questions:
  • Select the correct answer. What is the greatest common factor of this expression? 12m + 18m2 A. 6m B. 6 C. 2m D. 2
    15·2 answers
  • Solve this equation: please show all the work<br><br> <img src="https://tex.z-dn.net/?f=x%5E%7B3%7D-y%2B9-%28xy%29" id="TexFormu
    6·1 answer
  • Give the equation of the circle centered at the origin and passing through the point (0,4).
    15·1 answer
  • Rhoda is asked to graph this system of equations: 5x - 6y = 4 3y + 2x = 7 How many times will the lines intersect? O A. The line
    7·1 answer
  • THE FOLLOWING QUESTIONS ARE SUPER EASY - NO NEED TO SOLVE ALL: JUST CHOOSE ONE!
    5·1 answer
  • Pls help?!?!? With this
    14·1 answer
  • 6.71/(1.15)^4 doesn't equal 5.73
    7·2 answers
  • with an installment buying plan you take possession of the item and with layway plan you take possession of the item
    8·1 answer
  • Witch equation has the correct sign on the product.
    5·2 answers
  • Solve for x pls helppppp
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!