Answer:
a) 22.94 psi
b) 
Step-by-step explanation:
a)The pressure at which will trigger a warning is
31 - 31*0.26 = 22.94 psi
b) The probability that that the TPMS will trigger warning at 22.94 psi, given that tire pressure has a normal distribution with average of 31 psi and standard deviation of 2 psi

where x = 22.94, 


Let Ted be x.
Ed is 7 years older = x + 7
Ed = (3/4)Ted
(x + 7) = (3/4)x
x + 7 = 3x/4
x - 3x/4 = -7
x/4 = -7
x = -28, Ted = -28 years.
(x + 7) = -28 + 7 = -21, Ed = -21 years
Goodness. We had negative numbers for the ages, well does that make sense? No it doesn't.
Our answer is correct. But the sense in the question is lacking. The question has been wrongly set.
<span>We might assume negative ages to mean before they came into the world, before birth! </span>
Answer:
The value is 
The probability has increased
Step-by-step explanation:
From the question we are told that
The percentage that are from outside the country is 
The percentage that logs on everyday is 
The percentage that logs on everyday that are from the inside the country is 
Generally using Bayes' Rule the probability that a person is from the country given that he logs on the website every day is mathematically represented as

Where
is the percentage that are from inside that country which is mathematically represented as



And
is percentage that logs on everyday that are from the outside the country which is evaluated as




Given that the percentage that are from inside that country is 
and that the probability that a person is from the country given that he logs on the website every day is 
We see that the additional information increased the probability
1 file -> 12 sheets
Now for 3 files -> 3*12 = 36 sheets, it takes up 2/3 of the total
So the total number of sheets: 36 / (2/3) = 54