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
dolphi86 [110]
4 years ago
5

Suppose we want a 90% confidence interval for the average amount of time (in minutes) spent per week on homework by the students

in a large introductory statistics course at a large university. The interval is to have a margin of error of 3 minutes, and the amount spent has a Normal distribution with a standard deviation σ = 40 minutes. The number of observations required is closest to:
1180.
683.
482.
22.
Mathematics
1 answer:
ki77a [65]4 years ago
5 0

Answer: 482

Step-by-step explanation:

Formula to find the sample size is given by :-

n= (\dfrac{z^*\times \sigma}{E})^2                                    (1)

, where z* = critical z-value (two tailed).  

\sigma = Population standard deviation and E = Margin of error.

As per given , we have

Margin of error : E= 3

\sigma=40

Confidence level = 90%

Significance level =\alpha=1-0.90=0.10

Using z-table , the critical value for 90% confidence=z^*=z_{\alpha/2}=z_{0.05}=1.645

Required minimum sample size = n= (\dfrac{(1.645)\times (40)}{3})^2   [Substitute the values in formula (1)]

n=(21.9333333333)^2

n=481.07111111\approx482  [ Round to the next integer]

Hence, the number of observations required is closest to 482.

You might be interested in
Which function is represented by the graph?
belka [17]
Any equation where you have a y and a x
4 0
3 years ago
Read 2 more answers
3. A sample of 50 different-colored golf balls was removed from the total number of
Paraphin [41]

Answer:

C. 350

Step-by-step explanation:

A sample of 50 different coloured balls are removed from total golf balls made.

Out of these 50 coloured balls, 8 balls are pink

Now, to calculate the total number of golf balls made,

we can use the concept of proportion

\frac{number of pink colored balls in sample}{total pink colored balls made} = \frac{number of golf balls taken out as a sample}{ total number of golf balls made}

\frac{8}{56} = \frac{50}{total golf balls made}

total golf balls made = \frac{50\times56}{8}

total golf balls made = 350

5 0
3 years ago
What is the rewritten equation with the common denominator for 1/2 + 1/6?
larisa [96]
I believe it’s 3/6 + 1/6 which would equal 4/6 or 2/3
4 0
3 years ago
Order these numbers from least to greatest.<br> 17<br> 9<br> 8.49,8<br> 20<br> 7.479,<br> 2
nexus9112 [7]
2, 7.479, 8, 8.49, 9, 17, 20
3 0
3 years ago
Read 2 more answers
A triangle has two side of length 10 and 14 what value could the length of the third side be check all that apply
expeople1 [14]

If a, b and c are the lengths of the sides of a triangle then

if a ≤ b ≤ c, then a + b > c.

A) 10, 14, 26

10 + 14 = 24 < 26   INCORRECT  :(

B) 10, 14, 16

10 + 14 = 24 > 16  CORRECT :)

C) 10, 10, 14

10 + 10 = 20 > 14  CORRECT :)

D) 8, 10, 14

8 + 10 = 18 > 14   CORRECT :)

E) 5, 10, 14

5 + 10 = 15 > 14   CORRECT :)

F) 2, 10, 14

2 + 10 = 12 < 14   INCORRECT :(

<h3>Answer: B) 16, C) 10, D) 8, E) 5</h3>
8 0
3 years ago
Other questions:
  • A restaurant has 75% of its tables being used. Which ratio compares the used tables with all the tables in the restaurant?
    15·2 answers
  • If a triangle has three congruent sides, then its angles are all 60 degrees. Identify each statement by matching it to the corre
    15·1 answer
  • A cylinder has a volume of 245 cubic units and a height of 5 units. The diameter of the cylinder is
    8·2 answers
  • If 2x + a=b solve for x.
    9·1 answer
  • Fraction 353/8 simplified
    6·1 answer
  • PLEASE HELP!! a cylinder has a radius of 2x + 3 and a height of 6x + 1. Which polynomial in standard form best describes the tot
    15·1 answer
  • Month. Find his monthly income and expenditure.
    8·1 answer
  • Must include an explanation !!<br><br> solve for x
    15·1 answer
  • Solve c. 89=8c+25 and have a bless day
    13·1 answer
  • solve the problem.a ball is kicked upward with an initial velocity of 68 feet per second. the ball's height, h (in feet), from t
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!