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
ELEN [110]
3 years ago
12

In order to estimate the average time spent on the computer terminals per student at a local university, data were collected fro

m a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.2 hours. Calculate the margin of error (to two decimals) for a confidence interval with a confidence coefficient of 0.95.
Mathematics
1 answer:
VladimirAG [237]3 years ago
4 0

Answer:

Margin of error  for a 95% of confidence intervals is 0.261

Step-by-step explanation:

<u>Step1:-</u>

 Sample n = 81 business students over a one-week period.

 Given the population standard deviation is 1.2 hours

 Confidence level of significance = 0.95

 Zₐ = 1.96

Margin of error (M.E) = \frac{Z_{\alpha  }S.D }{\sqrt{n} }

Given n=81 , σ =1.2 and  Zₐ = 1.96

<u>Step2:-</u>

<u />Margin of error (M.E) = \frac{Z_{\alpha  }S.D }{\sqrt{n} }<u />

<u />Margin of error (M.E) = \frac{1.96(1.2) }{\sqrt{81} }<u />

On calculating , we get

Margin of error = 0.261

<u>Conclusion:-</u>

Margin of error  for a 95% of confidence intervals is 0.261

<u />

You might be interested in
Angles A and B are complementary and in ratio of 3:6. What is the measure of each angle
pashok25 [27]

complementary angles add up to 90°, so therefore we know that ∡A + ∡B = 90°, and also they are in a ratio of 3:6.


\bf \cfrac{A}{B}=\cfrac{3}{6}\implies \cfrac{A}{B}=\cfrac{1}{2}\implies 2A=\boxed{B}&#10;\\\\[-0.35em]&#10;~\dotfill\\\\&#10;A+B=90\implies A+\boxed{2A}=90\implies 3A=90\\\\\\ A=\cfrac{90}{3}\implies \blacktriangleright A=30 \blacktriangleleft&#10;\\\\[-0.35em]&#10;\rule{34em}{0.25pt}\\\\&#10;2(30)=B\implies \blacktriangleright 60=B \blacktriangleleft

7 0
3 years ago
How do you solve his with working
AlexFokin [52]
Check the picture below.

a)

so the perimeter will include "part" of the circumference of the green circle, and it will include "part" of the red encircled section, plus the endpoints where the pathway ends.

the endpoints, are just 2 meters long, as you can see 2+15+2 is 19, or the radius of the "outer radius".

let's find the circumference of the green circle, and then subtract the arc of that sector that's not part of the perimeter.

and then let's get the circumference of the red encircled section, and also subtract the arc of that sector, and then we add the endpoints and that's the perimeter.

\bf \begin{array}{cllll}&#10;\textit{circumference of a circle}\\\\ &#10;2\pi r&#10;\end{array}\qquad \qquad \qquad \qquad &#10;\begin{array}{cllll}&#10;\textit{arc's length}\\\\&#10;s=\cfrac{\theta r\pi }{180}&#10;\end{array}\\\\&#10;-------------------------------

\bf \stackrel{\stackrel{green~circle}{perimeter}}{2\pi(7.5) }~-~\stackrel{\stackrel{green~circle}{arc}}{\cfrac{(135)(7.5)\pi }{180}}~+&#10;\stackrel{\stackrel{red~section}{perimeter}}{2\pi(9.5) }~-~\stackrel{\stackrel{red~section}{arc}}{\cfrac{(135)(9.5)\pi }{180}}+\stackrel{endpoints}{2+2}&#10;\\\\\\&#10;15\pi -\cfrac{45\pi }{8}+19\pi -\cfrac{57\pi }{8}+4\implies \cfrac{85\pi }{4}+4\quad \approx \quad 70.7588438888



b)

we do about the same here as well, we get the full area of the red encircled area, and then subtract the sector with 135°, and then subtract the sector of the green circle that is 360° - 135°, or 225°, the part that wasn't included in the previous subtraction.


\bf \begin{array}{cllll}&#10;\textit{area of a circle}\\\\ &#10;\pi r^2&#10;\end{array}\qquad \qquad \qquad \qquad &#10;\begin{array}{cllll}&#10;\textit{area of a sector of a circle}\\\\&#10;s=\cfrac{\theta r^2\pi }{360}&#10;\end{array}\\\\&#10;-------------------------------

\bf \stackrel{\stackrel{red~section}{area}}{\pi(9.5^2) }~-~\stackrel{\stackrel{red~section}{sector}}{\cfrac{(135)(9.5^2)\pi }{360}}-\stackrel{\stackrel{green~circle}{sector}}{\cfrac{(225)(7.5^2)\pi }{360}}&#10;\\\\\\&#10;90.25\pi -\cfrac{1083\pi }{32}-\cfrac{1125\pi }{32}\implies \cfrac{85\pi }{4}\quad \approx\quad 66.75884

7 0
3 years ago
9. If f(x)=-2x^2+4x-6, <br> then f(2)=
Romashka-Z-Leto [24]

Answer:

f(2) = -6

General Formulas and Concepts:

Order of Operations: BPEMDAS

Substitution and Evaluation

Step-by-step explanation:

<u>Step 1: Define</u>

f(x) = -2x² + 4x - 6

f(2) is x = 2

<u>Step 2: Solve</u>

  1. Substitute:                          f(2) = -2(2)² + 4(2) - 6
  2. Exponents:                         f(2) = -2(4) + 4(2) - 6
  3. Multiply:                              f(2) = -8 + 8 - 6
  4. Add:                                    f(2) = -6
3 0
3 years ago
HEYYYY GUYYYSSS HELPP MEEE, ILL MARK YOU BRAINIEST. PLEEEAAASEEEE thankkyouu
VikaD [51]

Answer:

Step-by-step explanation:

A dependent variable in an expression is one whose value can be determined only when the value of other variable (i.e independent) is known.

A. The cost at the fitness center depends on the number of months (x).

The cost is the dependent variable, and number of months (x) is the independent variable.

f(x) = 100 + 40x

Example, the cost paid for 12 months can be determined as;

f(12) = 100 + 40(12)

       = 100 + 480

       = 580

Thus, $580 would be paid for 12 months at the fitness center.

B. The lettuce is sold at $1.69 per pound. The cost depends on the number of pounds of lettuce bought.

The cost is the dependent variable, while the number of pounds of lettuce (x) bought is the independent variable.

So that;

f(x) = 1.69x

The cost of 10 pounds of lettuce can be determined as;

f(x) = 1.69(10)

     = 16.9

Thus, the cost of 10 lb of lettuce is $16.90.

6 0
2 years ago
Kelly walks 0.7 mile to school. Mary walks 0.49 mile to school. Write an inequality using &lt;,&gt;, or = to compare the distanc
katrin2010 [14]
0.7 > 0.49
hope this helps
8 0
3 years ago
Other questions:
  • 12 foot tall street light is making a 18 foot shadow at the same time a nearby building is making a 72 feet shadow. How y’all
    9·1 answer
  • The sum of two consecutive odd integers is 28. What are the integers?
    13·1 answer
  • Tell if each number is divisible by 2,3,4,5,6,7,8,9,10 ☝️
    15·1 answer
  • Which one of the following statements expresses a true proportion?
    10·1 answer
  • What did the Concordat of 1801 accomplish?
    15·1 answer
  • I don't understand this Geometry question. Can someone help, please?
    11·1 answer
  • Offering Brainliest , a 5 star review, and a like on your answers if you can successfully answer these last 2 simple coordinate
    6·2 answers
  • Determine the domain of the function in the picture below
    11·1 answer
  • Please help this is timed
    5·1 answer
  • One hundred thirty people were asked to determine how many cups of fruit and water they consumed per day. the results are shown
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!