Answer:
68% of these phones last 3.87 years.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:

In which
is the decay parameter.
The probability that x is lower or equal to a is given by:

Which has the following solution:

The probability of finding a value higher than x is:

The average lifetime of a certain new cell phone is 3.4 years.
This means that 
So

68% of these phones last how long (in years)?
This is x for which:


Then






68% of these phones last 3.87 years.
-5/4
The ‘rise’ is 5 units, but it goes down so it is negative.
The ‘run’ is 4 units to the right.
Rise
———
Run
-5/4
Answer:

Step-by-step explanation:
Hi!
The options regarding the inequalities are not listed, though we can still proceed to write the inequality.
From the problem statement you cannot spend more than $50
and you are charged admission fee of $6 flat
a ride cost $2.50 per ride
the number of rides is given as r
yet in all you must not go beyond your limit
Therefore the inequalities can be presented as
