### MS 150 Statistics t2 • Name:

refraction
index
1.56
1.49
1.47
1.41
1.34
1.29
1.25
1.22
1.23
1.12
1.10
1.08

During an index of refraction of water laboratory one laboratory group gathered the data in the table.

1. __________ What level of measurement is the data?
2. __________ Find the sample size n for the data.
3. __________ Find the minimum.
4. __________ Find the maximum.
5. __________ Find the range.
6. __________ Find the midrange.
7. __________ Find the median.
8. __________ Find the mode.
9. __________ Find the sample mean x.
10. __________ Find the sample standard deviation sx.
11. __________ Find the sample coefficient of variation CV.
12. ____________________ Calculate the standard error of the mean.
13. Calculate the 95% confidence interval for the population mean index of refraction.

p(__________ < μ <__________) = 0.95
14. ____________________ The index of refraction of water quoted by textbooks is 1.33. Is 1.33 a possible population mean value based on the data gathered by the lab group?
Confidence interval statistics
Statistic or ParameterSymbolEquationsOpenOffice
Degrees of freedomdfn-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 < 30 using sx. Should also be used for n ≥ 30. E =tc*sx/SQRT(n)
Calculate a confidence interval for a population mean μ from a sample mean x and an error tolerance E x - E ≤ μ ≤ x + E