Copyright © 2016 Dept. of Statistics and Data Sciences, UT Austin
Biostats SDS 328M Homework 4
(all work must be done by hand).
Write your answers onto one or more separate sheets of paper. Clearly mark each sheet
with your name and your lab time.
Round all answers to at least 3 decimal places and assume
that α=0.05 unless
In a study of nerve cells, researchers measured the timing of spontaneous electrical
discharges in a single organism. The interspike-time intervals were approximately
normally distributed with a mean of 15.28 ms and a standard deviation of 0.39 ms.
Suppose you measured a random sample of
= 5 interspike-time intervals from this
What is the probability that all five times in your sample are between 15.00 and
What is the probability that the sample mean time for your sample is between
15.00 and 15.50 ms?
Comparing the probabilities you calculated in parts (a) and (b), which is larger?