Assume that the time interval between customers entering your store can be modeled using anexponential distribution. You know that you have an average of 4customers per minute, so therateis 4, or you can say that lambda = 4according to Yakir (2011, p. 79-80).

What is the expectation for the time interval between customers entering the store?Be sure to specify the units of measurement in your answer (see Yakir, 2011, pp. 79-80).Round to 3 decimal places: ___________________

What is the variance of the the time interval?Be sure to specify the units of measurement in your answer. Round to 3 decimal places:_________________

The pexp() function is introduced at the bottom of Yakir, 2011, p. 79, and there are some tips above.What is the probability that the time interval between customers entering the store will be less than 15.5 seconds. Be sure to enter values so that everything is in the same unit of measurement.Be sure to specify the units of measurement in your answer.Round your answer to 3 decimal places: _________________.

What is the probability that the time interval between customers entering the store will be between 10.7 seconds and 40.2 seconds (see Yakir (2011, p. 79-80)?________

The qexp() function in R allows you to enter a probability, and it will tell you the criterion value ("cutoff point") that corresponds to that probability value (e.g., if you enter .05 it tells you the cutoff point below which 5% of the values in the distribution fall).

What value ofxwould be the criterion value (cut-off point) for the top 5% of time intervals (Round to 3 decimal places, and include the units of measurement)? _______

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Describe the meaning of the number that the following R command produces pexp(1.2, rate=3)

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