StatCrunch: Hypothesis Tests and Confidence Intervals for Two Means with Summary Data Video Lecture | Statcrunch Tutorials for Beginners - Data & Analytics

in this video you will learn to compute
hypothesis tests and confidence
intervals for the difference between two
means with summary data using statcrunch
in this example I will compare randomly
sampled four bedroom homes listed for
sale and two adjoining cities Bryan
Texas and College Station Texas a random
sample of 15 homes listed for sale in
Bryan Texas was found to have a mean
square footage of 2842 square feet and a
sample standard deviation of 831 square
feet a random sample of 15 homes in
College Station Texas was found to have
a mean of 2751 square feet and a sample
standard deviation of 774 square feet
this video will cover how to compute a
two sample T hypothesis test and a two
sample T confidence interval a similar
approach can be used for two sample Z
methods that are the appropriate for the
situations with larger sample sizes
and/or known standard deviations for
this video the statistical question I am
going to test is is there a significant
difference in the average size of four
bedroom homes listed for sale in the two
cities to do so under the stat menu I'll
choose T stats to sample with summary
under sample one I'm going to enter 2842
for the mean 831 for the sample standard
deviation and the sample size is 15 for
sample two the sample mean is 2751 the
sample standard deviation is 774 and the
sample size is again 15
notice under the perform menu by default
the hypothesis tests option is chosen
for this example we'll leave the null at
zero for the alternative hypothesis you
could have not equal to less than or
greater than
for this example I'll leave it at not
equal to I'll click compute the output
table provides various statistics from
the test including the test statistic
and the p-value now instead of computing
a hypothesis test let's compute a
confidence interval for the difference
between the two means to do so under
options choose edit this takes us back
to the original window where we set up
our test and this window statcrunch has
other options for the user to choose
this time under the perform area I'm
going to choose confidence interval by
default statcrunch has a value of zero
point nine five for the level which will
produce a 95% confidence interval for
the difference between the two means for
this example I'll enter 0.99 which will
produce a 99% confidence interval I'll
click compute the result now shows a 99%
confidence interval for the difference
in the mean square footage of four
bedroom homes where L limit represents
the lower limit and you limit represents
the upper limit of the confidence
interval