SOLUTION: a study was conducted in oder to determine if any link existed between cellular phone usage and the development of brain cancer. Data from this study indicate that normally phone u
Algebra.Com
Question 568103: a study was conducted in oder to determine if any link existed between cellular phone usage and the development of brain cancer. Data from this study indicate that normally phone usage for all users is approximately normally distributed with mean 2.4 hours and standard deviation 1.1 hours.
a. what proportion of cell phone users are on their phones between 1 hour an 3 hours per month?
b. just to be safe, suppose you decide to be in the 5th percentile of cell phone users in terms of monthly usage. how much time can you spend on the phone this month?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
a study was conducted in order to determine if any link existed between cellular phone usage and the development of brain cancer. Data from this study indicate that normally phone usage for all users is approximately normally distributed with mean 2.4 hours and standard deviation 1.1 hours.
a. what proportion of cell phone users are on their phones between 1 hour an 3 hours per month?
z(1) = (1-2.4)/1.1 = -1.2727
z(3) = (3-2.4)/1.1 = 0.5455
---
P(1 <= x <= 3) = P(-1.2727<= z <= 0.5455) = 0.6057
--------------------------------------------------------------
b. just to be safe, suppose you decide to be in the 5th percentile of cell phone users in terms of monthly usage. how much time can you spend on the phone this month?
Ans:invNorm(0.05) = -1.645
----
x = zs + u
x = -1.645*1.1 + 2.4 = 0.5905 hours = 35.43 minutes
===================
Cheers,
Stan H.
===================
RELATED QUESTIONS
The profit P (in dollars) on each cellular phone manufactured by Clear Line Inc., is... (answered by solver91311)
In a certain town, 50% of the residents own a cellular phone, 40% own a pager, and 20%... (answered by stanbon)
the profit P (in dollard) on each cellular phone manufactured by clear line inc. is... (answered by ikleyn)
In a study of 420,095 cell phone users in Denmark, it was found 135 developed cancer of... (answered by stanbon)
A survey was conducted to study the effects of weight loss from a low fat diet. Two... (answered by stanbon)
In a certain town, 75% of the households own a cellular phone, 45% own a laptop and 40%... (answered by fractalier)
study was conducted to see whether monetary incentives to use less water during times of... (answered by Boreal)
An MTN Cellular phone user notices that he cellular phone accounts of three consecutive... (answered by josgarithmetic)
A random sample of 50 households was selected for
a telephone survey. The key question... (answered by Boreal)