In: Statistics and Probability
The percent of persons (ages five and older) in each state who
speak a language at home other than English is approximately
exponentially distributed with a mean of 13.61.
Let X be the percent of persons (ages five and older) in each state who speak a language at home other than English.
X is exponentially distributed with mean 13.61.
a) If lambda is the parameter of X, we know that the expected value of X is
ans: the lambda of this distribution is 1/13.61
b) The probability density function (pdf) of X is
The cumulative distribution function of X, or P(X<=x) is
The probability that the percent is larger than 4.36 is
ans: The probability that the percent is larger than 4.36 is 0.7259
c) The probability that the percent is less than 14.22 is
ans: The probability that the percent is less than 14.22 is 0.6482
d) The probability that the percent is between 10.61 and 14.61 is
ans: The probability that the percent is between 10.61 and 14.61 is 0.1168