SOLUTION: A mobile phone company finds the lifespan for one brand of its mobile phones is normally distributed with a mean of 48,400 hours (approx. 5.5 years) and a standard deviation of 500

Algebra.Com
Question 1185533: A mobile phone company finds the lifespan for one brand of its mobile phones is normally distributed with a mean of 48,400 hours (approx. 5.5 years) and a standard deviation of 5000 hours.


Answer the following:
If the manufacturer is willing to replace no more than 10% of the mobile phones, what should be the approximate number of hours for a warranty? Note: Express your answer in whole number.
What is the probability that a mobile phone will last between 36,400 hours and 44,400 hours? Note: Express your answer in four decimal places.
What is the probability that a mobile phone will last at least 55,900 hours? Note: Express your answer in four decimal places.

Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
the calculator at https://davidmlane.com/hyperstat/z_table.html can help you find the answer to this.

mean = 48400
standard deviation = 5000

question 1:

If the manufacturer is willing to replace no more than 10% of the mobile phones, what should be the approximate number of hours for a warranty? Note: Express your answer in whole number.

the warranty should state that the approximate number of hours of life for the phone is guaranteed to be at least 41992.242

round to units to get 41992.

here are the results from the calculator.


question 2:

What is the probability that a mobile phone will last between 36,400 hours and 44,400 hours? Note: Express your answer in four decimal places.

the probability is equal to .2037

here are the results from the calculator.



question 3:

What is the probability that a mobile phone will last at least 55,900 hours? Note: Express your answer in four decimal places.

the probability is equal to .0668

here are the results from the calculator.



in question 1, you were looking for a value from an area.

in question 2 and 3, you were looking for an area from a value.

i confirmed with that the answers were consistent with the answers from my ti-84 plus scientific calculator.


RELATED QUESTIONS

1. A tire company finds the lifespan for one brand of its tires is normally distributed... (answered by ewatrrr)
A manufacturer makes mobile phones. The manufacturer employs an inspector to check the... (answered by stanbon)
A mobile phone manufacturer is promoting a new mobile because of its excellent battery... (answered by Boreal)
The duration of phone calls to a Calling Centre is normally distributed with a mean of... (answered by ewatrrr)
A survey of 4,581 U.S. households that owned a mobile phone found that 58 percent are... (answered by stanbon)
a random sample of 500 individuals selected from each of three grouped and each person... (answered by stanbon)
In a group of 20 students, five do not have a mobile phone. If three students are... (answered by stanbon)
A producer is planning to produce a new type of tyre. The fixed costs are sh 320million... (answered by josgarithmetic)
A manufacturer knows that their items have a normally distributed lifespan, with a mean... (answered by VFBundy)