__________ Find the sample coefficient of variation CV.
__________ If this data is divided into five bins, what is the width of a single bin?
Determine the frequency and calculate the relative frequency using five bins (classes, intervals). Record your results in the table provided.
Bin upper limits
Frequency F
Relative Frequency
Sums:
Sketch a frequency histogram of the data, labeling your horizontal axis and vertical axis as appropriate.
____________________ What is the shape of the histogram?
__________ The index of refraction for water is 1.33. Calculate the z-score for an index of refraction of 1.33 using the mean and standard deviation calculated above.
____________________ Is a z-score of 1.33 ordinary or unusual?
__________ The index of refraction for glass is 1.5. Calculate the z-score for an index of refraction of 1.5 using the mean and standard deviation calculated above.
____________________ Is a z-score of 1.5 ordinary or unusual?
____________________ What is the point estimate for the population mean μ?
____________________ Calculate the standard error of the mean SE.
____________________ Calculate the degrees of freedom n − 1.
____________________ Calculate t-critical tc for confidence levels of 95%.
____________________ Calculate the margin of error for the mean E.
Calculate the 95% confidence interval for the population mean μ total rainfall.
p(__________ ≤ μ ≤ __________) = 0.95
____________________ Does the 95% confidence interval include 1.33?
____________________ Refraction theory states that the index of refraction for water is 1.33. Is 1.33 a possible population mean μ for this sample at a confidence level of 95%?
____________________ Would we disconfirmorfail to disconfirm an index of refraction of 1.33 for water?
Confidence interval statistics
Statistic or Parameter
Symbol
Equations
OpenOffice
Degrees of freedom
df
n − 1
=COUNT(data)-1
Find a tcritical value from a confidence level c
tc
=TINV(1-c;df)
Standard error of the sample mean
SE
=STDEV(data)/SQRT(sample size n)
Calculate a margin of error for the mean E for n ≥ 5 using sx.
E
=tc*sx/SQRT(n)
Calculate a confidence interval for a population mean μ from a sample mean
x and an error tolerance E