1. Unit 3 Quiz: Review questions

2. Can you explain your answer?
Use your fingers to indicate your answer: 1=A, 2=B, 3=C, 4=D.
After viewing the question, show me your answer in 15 seconds.
Next, turn to your neighbor and you have one minute to convince him/her that you are right.

3. Usually a frequency distribution is depicted by a _____________.
Histogram
Pie chart
Scatterplot
All of the above

4. The tick marks in a histogram show the _____________ of the data values.
frequency
Interval
shape
All of the above

5. If a curve is symmetrical,_______.
most of the scores fall at the lower values of the X axis
most of the scores fall at the higher values of the X axis
if folded in half, the two sides of the curve coincide
most of the scores fall at the higher values of the Y axis

6. Dr. Lili Li is an aerospace engineer
Dr. Lili Li is an aerospace engineer. She compares the efficiency of a NASA rocket and a European made rocket. A critic charges that the study is invalid because she compared just one rocket from each manufacturer. What should the engineer reply?
Rockets are very expensive to make and she must bite the bullet to accept the sample-size limitation.
The study is valid because we should not expect a huge variation in high tech products that require a high degree of precision.
Ask President Trump to give more money to NASA so that they can build more rockets.
Every research project has limitations. So what!

7. What is the best and the most common way to report the central tendency of a normal distribution?
mean
median
mode
Standard deviation

8. What is the best way to report the central tendency of a skewed distribution?
mean
median
mode
Standard deviation

9. Which statistics can tell us the variation (dispersion) of the data?
Standard deviation
Variance
All of the above

10. What is the difference between the formulas for the sample standard deviation (SD) and the population SD?
In the formula of the sample SD we need to take the degree of freedom into account (n -1).
In the formula of the population SD we need to take the degree of freedom into account (n -1).
Both A and B are right