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
marysya [2.9K]
3 years ago
14

Listed below are student evaluation ratings of​ courses, where a rating of 5 is for​ "excellent." The ratings were obtained at o

ne university in a state. Construct a confidence interval using a 95​% confidence level. What does the confidence interval tell about the population of all college students in the​ state?
3.63.6​,


2.92.9​,


3.83.8​,


4.54.5​,


3.23.2​,


3.93.9​,


3.33.3​,


4.64.6​,


4.14.1​,


4.34.3​,


4.44.4​,


3.93.9​,


3.23.2​,


4.24.2​,


3.83.8
Mathematics
1 answer:
Dmitriy789 [7]3 years ago
3 0

Answer:

3.573 to 4.127

Step-by-step explanation:

Given

Sample size = 15

Mean = Sum of ratings/ sample size

Mean = 57.7/15

Mean = 3.85

Degree of freedom = sample size - 1

Degree of freedom = 15 - 1 = 14

df = 14

Then we calculate the standard deviation

(x - mean)² ||

(3.6 - 3.85)² || 0.0625

(2.9 - 3.85)² || 0.9025

(3.8 - 3.85)² || 0.0025

(4.5 - 3.85)² || 0.4225

(3.2 - 3.85)² || 0.4225

( 3.9 - 3.85)² || 0.0025

( 3.3 - 3.85)² || 0.3025

( 4.6 - 3.85)² || 0.5625

(4.1 - 3.85)² || 0.0625

(4.3 - 3.85)² || 0.2025

4.4 - 3.85)² || 0.3025

( 3.9 - 3.85)² || 0.0025

(3.2 - 3.85)² || 0.4225

( 4.2 - 3.85)² || 0.1225

( 3.8 - 3.85)² || 0.0025

Total || 3.7975

Variance = 3.7975/15 = 0.253167

Standard Deviation = √0.253167 = 0.50315703314174194

Standard Deviation = 0.5 ------- Approximated

The next step is to subtract the confidence level from 1, then divide by two.

i.e (1 - 0.95)/2 = 0.025

α = 0.025

Then we look up this answer to step in the t-distribution table.

For 14 degrees of freedom (df) and α = 0.025, my result is 2.145

The next step is to divide the sample standard deviation by the square root of the sample size.

0.5 / √15 = 0.129

Next is to multiply this result by step 2.145 (from the t table)

0.129 × 2.45 = 0.277

For the lower end of the range, subtract 0.277 from the sample mean.

3.85 – 0.277 = 3.573

Step 7: For the upper end of the range, add step 0.277 to the sample mean.

3.85 + 0.277 = 4.127

You might be interested in
Abigail is redecorating a master bathroom. The legend on the blueprint shows at 3 cm equals 9 m. What is the scale factor?
zaharov [31]
300:1. A meter is 100 cm, so 9 meters is 900 cm / 3 = 300.
3 0
3 years ago
Use a diagram to name each of the following pairs of angles. If the name doesn't exist say none​
nirvana33 [79]

Answer:

  see below

Step-by-step explanation:

This is a vocabulary problem, identifying the names of things on a diagram.

Angles are "interior" when they are between the "parallel" lines. They are "exterior" when they are outside those lines. They are "alternate" if they are on opposite sides of the transversal, and "same side" if they are not.

They are "vertical" if they share a vertex and have opposite rays for sides, and they are "corresponding" if they are in the same quadrant of the intersection of crossing lines. (1, 5, 9, 13 are "corresponding", for example.)

5 0
3 years ago
What is the area,in square yards of the rectangle shown down below 12yd 15yd Answer choices are 225,54,180,27
11Alexandr11 [23.1K]

Answer:

area of rectangle =length ×width

area of rectangle=12yd×15yd

area of rectangle=180yd²

5 0
3 years ago
Read 2 more answers
I am really bad at math. What is AC?
kotykmax [81]
The line from a to c
4 0
3 years ago
Read 2 more answers
What is the equation of the line that passes through the points (1,5) and (0,3)?
Pavlova-9 [17]

Answer:

y=2x+3

Step-by-step explanation:

first use the y2-y1/x2-x1 then use y=mx+b after

plug in 3 for y2 and 5 for y1

then plug in 0 for x2 and 1 for x1

\frac{3-5}{0-1}=\frac{-2}{-1} =2 and 2 is ur slope

___________________

now use y=mx+b

i usually use the first point but u can u anyone u want

plug in 1 for x

plug in 5 for y

and plug in 2 for m

5=2(1)+b

5=2+b

subtract 2 on both sides

5-2=3

3=b and b is ur y-intercept

y=2x+3

hope this helps

4 0
3 years ago
Other questions:
  • Whats is the product (6r-1)(-8-3)
    11·1 answer
  • if you have 245 cats and you sold 3.56% of it and got back 2.1% of what you sold how many cats do you have left
    11·1 answer
  • Simplify.<br><br> 8200−−−√−3162−−−√
    10·1 answer
  • (100 Points and Brainlest)
    11·2 answers
  • Jim has three times as many comic books as Charles. Charles has 2/3 as many books as Bob. Bob has 27 books. How many comic books
    14·2 answers
  • A spinner and 2 cards are shown below:
    15·2 answers
  • I need HALLLLPPPPPP asap
    12·1 answer
  • When writing an equation in slope-intercept form, you need the values of the
    5·1 answer
  • Use the circle below for questions 13-16
    15·2 answers
  • I need help with this please​
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!