Statistics
posted by Brad .
Suppose that the travel time from your home to your office is normally distributed
with a mean of 40 minutes and standard deviation of 7 minutes. If you want to be
95% certain that you will not be late for an office appointment at 1:00pm, what is the
latest time that you should leave home?

From a normal distribution table (example
http://www.math.unb.ca/~knight/utility/NormTble.htm
)
look up the zvalue for 95% probability, which is 1.645.
μ=40 minutes, σ=7 minutes.
Calculate n from the transformation of x to z as follows:
z=(xμ)/σ
x=σz+μ
Everything on the right hand side is know, so calculate x required. 
0.5
Respond to this Question
Similar Questions

statistics
the scheduled commuting time on Long Island Rail Road from Glen Cove to New York is 65 minutes. Suppose that the actual commuting time is uniformly distributed between 64 and 74 minutes. What is the probability that the commuting time … 
statistics
Suppose the amount of time it takes for statistics students to complete their midterm is normally distributed with a mean of 85.70 minutes and a standard deviation of 22.55 minutes. If 10 students are randomly selected, what is the … 
Stats
Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. Suppose a random sample of 25 ordering processes is selected. … 
statistics
The time required to travel downtown at am on Monday morning is known to be normally distrubted with a mean of 40 minutes and a standard deviation of 5 minute what is the probability that it will take less than 40 minutes? 
Statistics
A hospital claims that the mean waiting time at its emergency room is 25 minutes. A random sample of 16 patients produced a mean wait time of 27.5 minutes with a standard deviation of 4.8 minutes. Use the 1% level of significance to … 
statistics
Times for a surgical procedure are normally distributed. There are two methods. Method A has a mean of 28 Minutes and a standard deviation of 4 minutes, while B has a mean of 32 minutes and a standard deviation of 2 minutes. a)which … 
statistics
Waiting times at a doctor office are normally distributed with a mean of 35 minutes, and a standard deviation of 10 minutes. What is the chance a patient would have to wait over 50 minutes? 
statistics
Waiting times at a doctor office are normally distributed with a mean of 35 minutes, and a standard deviation of 10 minutes. 25% of the patients have to wait less than how many minutes? 
statistics
Let x denote the time taken to run a road race. Suppose x is approximately normally distributed with a mean of 190 minutes and a standard deviation of 21 minutes. If one runner is selected at random, what is the probability that this … 
Statistics
The time to fly between New York City and Chicago is normally distributed with a mean of 180 minutes and a standard deviation of 17 minutes. What is the probability that a flight is more than 200 minutes?