Finding Percentages Using Technology

This video tutorial teaches how to calculate the percentage of a population within a certain range using technology. It covers methods like the empirical rule, z-scores, and the use of spreadsheets and calculators. The tutorial explains the standard normal distribution and how to use Excel and calculators to find percentages, including using the normal CDF function for interval calculations.

Which method can be used to find percentages when values are exactly 1, 2, or 3 standard deviations from the mean?

• Statistics tables

• Technology tools

• Z-scores

• Empirical rule

What is the total area under the standard normal distribution curve?

• 0.5

• 0.75

• 1

• 2

If a z-score is -1.75, what is the area under the curve up to this z-score?

• 0.93

• 0.75

• 0.25

• 0.0401

In Excel, which value should you select when finding percentages?

• Standard deviation

• Mean

• True

• False

What percentage of males are taller than 68 inches if the area up to 68 inches is 0.25?

• 50%

• 93%

• 25%

• 75%

Which function on a calculator helps find the area between two values in a normal distribution?

• Normal PDF

• Normal CDF

• Standard deviation

• Z-score

If you don't have a specific lower bound, what should you do when using the normal CDF function?

• Use the mean as the lower bound

• Use a value far from the mean

• Use zero as the lower bound

• Use the upper bound as the lower bound