The age of a first grader on September 1 at Garden Elementary School is uniformly distributed from 5.8 to 6.8 years.

We randomly select one first grader from the class.

a. Define the random variable. X = _________

b. Graph the probability distribution.

c. f(x) = _________

d. μ = _________

e. σ = _________

f. Find the probability that she is over 6.5 years old.

g. Find the probability that she is between four and six years old.

Carbon-14 is a radioactive element with a half-life of about 5,730 years. Carbon-14 is said to decay exponentially. The decay rate is 0.000121. We start with one gram of carbon-14.
We are interested in the time (years) it takes to decay carbon-14.