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
Anna11 [10]
3 years ago
12

The manager of a fleet of automobiles is testing two brands of radial tires and assigns one tire of each brand at random to the

two rear wheels of eight cars and runs the cars until the tires wear out. The data (in kilometers) follow. Find a 99% confidence interval on the difference in the mean life.
Car Brand 1 Brand 2
1 37734 35202
2 45299 41635
3 36240 35500
4 32100 31950
5 37210 38015
6 48360 47800
7 38200 37810
8 33500 33215
(a) Calculate d=
(b) Calculate sD =
(c) Calculate a 99% two-sided confidence interval on the difference in mean life.
Mathematics
1 answer:
Darya [45]3 years ago
8 0

Answer:

Brand 1    Brand 2    Difference

37734       35202        2532

45299      41635         3664

36240      35500        740

32100      31950         150

37210       38015       −805

48360     47800        560

38200    37810          390

33500    33215        285

Sum of difference = 2532+ 3664+740+150 −805+  560 +390 +285 = 7516

Mean = d=\frac{7516}{8}

Mean = d=939.5

a) d= 939.5

\text{Sample Standard deviation, s} = \sqrt{\dfrac{(x-\bar{x})^2}{n-1}}

=\sqrt{\dfrac{(2532-939.5)^2+(3664-939.5)^2+(740-939.5)^2 ...+(285-939.5)^2}{8-1}}

=1441.21

b)SD= 1441.21

c)Calculate a 99% two-sided confidence interval on the difference in mean life.

confidence level =99%

significance level =α= 0.01

Degree of freedom = n-1 = 8-1 =7

So, t_{\frac{\alpha}{2}}=3.499

Formula for confidence interval = \left( \bar{X} \pm t_{\frac{\alpha}{2}} \times \frac{s}{\sqrt{n}} \right)

Substitute the values

confidence interval = 939.5 \pm 3.499 \times \frac{1441.21}{\sqrt{8}} \right)

confidence interval = 939.5 - 3.499 \times \frac{1441.21}{\sqrt{8}} \right) to  = 939.5 + 3.499 \times \frac{1441.21}{\sqrt{8}} \right)

Confidence interval −843.396\ to  2722.396

You might be interested in
What is -7+p=3 please give me a step by step explanation.
ozzi

Answer:

p=10

Step-by-step explanation:

1.add 7 on each side to cancel -7

2.add 7 and 3 together to get ten

5 0
3 years ago
Read 2 more answers
I wasn't at school when they were teaching theoretical and experimental experimental. can someone explain how it works and give
Alexandra [31]
Hey I am just like u I wasn't at school I have been waiting for 1 hour and Noone had answer me I am sad I am going to fail
5 0
3 years ago
What is the square root of 312​
pishuonlain [190]

Answer:±17.6635217326557

Step-by-step explanation:

5 0
3 years ago
plz hurry 82 points help plzThe rental rate for a power washer has a one time fee of $50 plus $25 for each day of the rental. Th
Sveta_85 [38]

Answer: y = 25x + 50

Explanation: the total cost if the rental is a linear function of the number of days of the rental (x). Each day costs $25, so that is the slope of the line. Since there is also a one-time fee, independent of the number of days, this amount $50 represents a vertical shift of the line on the graph, by 50. y=25x+50 is an algebraic expression of that.

6 0
3 years ago
Read 2 more answers
The temperature started at 35 F. If the temperature went down 4°F and then up 2 F, whats is the temperature differe relative to
sashaice [31]
35-4+2 = 31+2 = 33 F
6 0
3 years ago
Read 2 more answers
Other questions:
  • Factor the Expression x^2+x+7
    6·1 answer
  • solve the equation below for y. 8x − 2y = 24 a. y = 4x − 12 b. y = 12 − 4x c. y = 8x − 24 d. y = 4x − 8
    13·1 answer
  • Micah's gym is moving into a bigger space, where he can have more stationary bicycles and treadmills. Micah needs both stationar
    15·1 answer
  • What is the volume of a shipping cube with dimensions of 2 and 1/2 feet
    13·1 answer
  • 2. Solve the following 10/12 - 4/3
    11·1 answer
  • Help me please!!!!!!!
    6·1 answer
  • Please help me lol.
    8·1 answer
  • Which expression is equivalent to 6.317x+ 19?
    8·2 answers
  • Pedro had $14.90 in his wallet. He spent $1.25 on a drink. How much does he have left?
    14·1 answer
  • Halpppppppp <br> -<br> -<br> -<br> -<br> -
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!