We want to find the probability that an athlete throws the hammer no less than 55 feet given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet.
We know that 55 is 1 stand deviation above the mean which is 50.
By the empirical rule, 68% of the distribution is within 1 standard deviation of the mean.
In this case only one standard deviation above the mean will give 34% .
So the probability that he throws the hammer less than 55 feet is 0.5+0.34=0.84
The probability that he throws it no less than 55 feet is 1-0.84=0.16
The rule for this sequence is 3n (n times 3). Simplying multiplying by 3 until you get to the 11th term (54 * 3 * 3 * 3 * 3 * 3 * 3), would give you this answer.
