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
just olya [345]
3 years ago
14

The mean lifetime of a certain tire is 30,000 miles and the standard deviation is 2500 miles. If we assume nothing about the sha

pe of the distribution, approximately what percentage of all such tires will last between 25,000 and 37,500 miles?
Mathematics
1 answer:
kati45 [8]3 years ago
5 0
A standard deviation is 2500 miles, so the range of 25,000 to 37,500 is 2 standard deviations below, and 3 standard deviation above the mean of 30,000. 
We aren't assuming anything about the distribution, but we sort of have to assume a normal distribution in order to answer. When you don't know anything about a distribution, this is generally what you do.
The general rule for standard deviations is:
+/- 1 SD: +/- 34% of population, for a total of 68%
+/- 2 SD: Another 14% in either direction, for a total of 96% of population.
+/- 3 SD, Another 2% in either direction, which pretty much captures the entire distribution (4 standard deviations from the mean is incredibly rare/unlikely) 
We have a range of +/- 1 SD, so we know that 68% percent o the tire 'population' is captured in the range. We also have one more standard deviation in both directions, so we add 28% to this number to get 96% of the population. We have a third standard deviation above the mean, so we add another 2% to arrive at 98% of the population. 

Answer is 98% of all such tires. 
You might be interested in
Solve the system of equations: <br> X+y+z=5<br> -3x-4y+4z=15<br> 2x-y-4z=-8
kolezko [41]

Answer:

Solution By Gauss jordan elimination method

x = 3, y = 2 and z = 4

6 0
2 years ago
A machine fills containers with 35 ounces of raisins
erica [24]
What’s the question?
3 0
3 years ago
The morse code is "FOUR BEFORE DECIMAL" I need help with the math problem and how FOUR BEFORE DECIMAL fits into it
sdas [7]

Answer:

the answer is 113.5

Step-by-step explanation:

rate brainliest!

5 0
2 years ago
Read 2 more answers
A bicycle tire has a radius of 13 1/4 inches. How far will the bicycle travel in 40 rotations of the tire? Round to the nearest
Sergeu [11.5K]

Answer:

the bicycle will travel 277.5 feet or 3,330.1 inches.

Step-by-step explanation:

the circumference(distance around a tire) is calculated by multiplying a circles diameter by pi. the diameter is twice the length of the radius.

so if you multiply 13 1/4 by 2 you get 26 1.5 if you multiply that by pi than you get the circumference. then multiply this by 40 to get the inches traveled and divide that by 12 to get the number of feet traveled.

8 0
3 years ago
Ms. Pacheco, Mr Edwards, and Mr Richards are three math teachers at turner middle school. Ms. Pacheco is three years older than
zubka84 [21]
Mr edwards = Mr r x 2
Mr r = Mr p - 3 = Mr e ÷ 2.                       Mr p = 30
Mr e + Mr r = 81.                                       Mr e = 54
Mr p = Mr r + 3.                                         Mr r = 27

Mr Edwards = 2(Mr p - 3)
Mr e = 2(mr p) - 6

Mr r = [2(Mr p) -6] ÷ 2
Mr r = [2( Mr r + 3) - 6] ÷ 2

2(Mr r) + (Mr p - 3) = 81
2(Mr p -3) + (Mr p - 3) = 81
3(Mr p - 3) = 81 
3(Mr p) - 9 = 81.                               Hope this helps!!!
3(Mr p) + 9 = 81 + 9
3(Mr p) = 90
Mr p = 90 ÷ 3
Mr p = 30


5 0
3 years ago
Read 2 more answers
Other questions:
  • please help me with these, show work or type how to do it ! Thank u, and yes I know they are wrong :/
    14·1 answer
  • Mrs. Miller sells a house for $179,000. If she earns a commission of 6% how much money does she earn? write a proportion and sho
    9·2 answers
  • A volleyball player serves the ball from a height of 6.5 feet above the ground with an initial vertical velocity of 21 feet per
    14·1 answer
  • When Liz woke up in the morning, it was 6°F. By the late afternoon, the temperature had dropped 9°F.
    15·1 answer
  • What is the radius of the circle x2+(y+6)2=25
    15·1 answer
  • Simplify the given expression. –10xy(4xy3 – 7xy + 9y2)
    14·1 answer
  • What is the slope and y-intercept of the graph?
    15·1 answer
  • To survey teens about their music presences you would question several teens
    10·1 answer
  • 7. A caterer knows there is one broken egg in every 3 cartons. A carton contains 12 eggs.
    12·1 answer
  • Your Roasted Snout dinner cost you $45.99. You will tip your server 15% of the bill. What is the TOTAL cost of your bill (includ
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!