STAT 200 quiz weeks complete solutions correct answers key

STAT 200 quiz weeks complete solutions correct answers key

1. You are a company’s Quality Assurance Specialist.  They make eyeglass frames.  You have 10 open boxes each containing 20 frames.  You select 4 boxes and inspect 2 frames in each box.  This is what type of sampling?  Justify you answer.

2. Draw what a Normal Distribution looks like, then one with a posisive skew and finally one with a negative skew:

3.  If you had data on the cost per square foot of carpetting, how would you lable the horixzontal and vertical axes?

4.  For the scores 3, 5, 8, 10, 13, 18, 21, 25, calculate the 75th percentile using the following formula: R = P/100 x (N + 1) and if R is not a whole number handle the fraction.

5. For the following data COMPUTE THE (ƩX)²  AND THE ƩY²

X

Y

3

2

6

5

9

6

6.  The numbers in this Stem 7 Leaf diagram go from 19 to _____.  Then, how many numbers are between 51 and 60 (not counting 51 or 60).  

7. Here are the heights (inches)of 10 men and 10 women:   (men): 68, 69, 72, 67, 68, 69, 73, 72, 80, 79  (women) 60, 62, 64, 65, 65, 65, 68, 69, 69, 71

Draw a (combined not individual) Stem and leaf display that compares these TWO groups of data.

8.  Draw a box plot and lable the significant parts of it (what data statistics are they)

9.  Look at this bell shaped curve of the Normal Distribution: 

(a) Why does neither end touch zero?

(b) If this were a Standardized curve, what would be the mean? And the numbers along the base (x-axis) would be the what?

10. (a) Here are the actual ages of 5 dogs in the shelter:  5, 7, 9, 7, 5  Plot these as a BAR CHART  What type of data are these exact ages?

(b) Here are the average ages of dogs in 5 shelters:  5.3, 7.2, 9.1, 7.6, 5.7  Plot these as a HISTOGRAM What type of data are these averages?

(c)  When should we use a Bar Chart and when a Histogram?

11. Here are the average hours a day (made up) an average UMUC student: sleeps(6), does stat HW (4), works (8), eats (3), does household chores (3), relaxes (4).  Draw a PIE CHART showing this hourly distribution.  Hint:  A circle has 360 degrees and represents the entire day.  What is the percent of a day each category is?  Go from there to get the size of the various pie slices  BE PRECISE and give the degrees out of 360 you determined for each slice.

12.  Here are 8 numbers:   3, 5, 7, 9, 15, 5, 7, 1

Determine the MEAN, VARIANCE and Standard Devaition BY HAND  (of course you can use a calculator for the multiplications and divisions, but not software that does it all)

13.  What are the RANGE, MODE, MEDIAN and Q1 and Q3 of this data set?

14.  Draw a BOX PLOT for this data set

15.  What is the IQR of this data set?

16.  Using the TWO methods for determining OUTLIERS (mean + 2 SD’s and the Q3 + 1.5 * IQR) are there ANY outliers at either end?