## Exam 1 Results

Mean | 90.5 |

Median | 95.0 |

Mode | 94.6 |

Standard Deviation | 15.8 |

Range | 100.0 |

Minimum | 0.0 |

Maximum | 100.0 |

Sum | 9047.7 |

Count | 100.0 |

Category: f19-busad265

- 4 years ago
- f19-busad265
- Justin

Mean | 90.5 |

Median | 95.0 |

Mode | 94.6 |

Standard Deviation | 15.8 |

Range | 100.0 |

Minimum | 0.0 |

Maximum | 100.0 |

Sum | 9047.7 |

Count | 100.0 |

- 4 years ago
- f19-busad265
- Justin

Review:

- Normal Curve problems
- Exam 1 on Wed Sep 18

Presentation:

- Exam format
- Open note, open book, open calculator
- No phones, laptops, tablets, watches
- No “sharing” with your neighbor
- No leaving the classroom during the exam

- Review Topics
- Data distributions
- Stemplots
- Histograms

- Measures of Central Tendency
- Mean
- Median
- Percentiles, Quartiles
- 5-number summary

- Measure of spread/variability
- Variance
- Standard Deviation

- Normal Distribution
- Standard Normal
- Z-Scores
- Z-table

- Normal Curve problems
- “Less than”
- “Greater than”
- “Between”
- Inverse or Reverse look-up (solve for X instead of Z)

- Data distributions

Activity:

- Practice exam: F18 BA265 Practice Exam 1a

Assignment:

- Study for Exam 1

- 4 years ago
- f19-busad265
- Justin

Review:

Presentation:

Solving Normal Curve Problems

- Video (0:45-3:45, 6:10-11:45)
- Find probabilities for Z-Scores with the Z-Table (use this link or back page of textbook)
**Normal Distribution Problems: 3 Types**- p(X<a) = “Less Than”
- p(X>b) = “Greater Than”
- p(a<X<b) = “Between” (between 2 values)

**Steps to finding Standard Normal Proportions**- Draw a picture of the distribution
- Convert given values (a, b) to Z-Scores and locate on the horizontal axis
- Look up corresponding proportion in the Z-Table
- Decide if it’s a “Less Than”, “Greater Than” or “Between” problem
- If “Less Than”, shade under the curve to the left of Z-Score; the Z-Table proportion you found is the answer.
- If “Greater Than”, shade under the curve to the right of the Z-Score; subtract the Z-Table probability from 1 to find the answer.
- If “Between”, you will have 2 proportions from the Z-Table
- Shade the area under the curve between the two Z-Scores
- Find the proportion for the larger value (further to the right)
- Find the proportion for the smaller value (further to the left)
- Subtract the smaller from the larger to find the “Between” proportion

**Inverse Normal Curve calculations**- Z = (x – xbar)/s
- x = xbar + Z * s
- xbar = mean
- s = standard deviation

- Problem Examples (see pp. 63-67)
- What proportion of observations on a standard Normal curve are less than Z=1.47?
- Using
**N(1026,209)**…- What proportion of students who take the SAT have scores of at least 820?
- What proportion of students who take the SAT would be NCAA “partial qualifiers”, i.e., between 720 and 820.
- What score is necessary to place in the top 10% of all students taking the SAT?

Activity:

**Problem 1**- In a recent year, 10th grade students took a standardized English language exam. The mean score was 572 and the standard deviation was 51, i.e.,
**N(572,51).**- What proportion of students scored less than 600?
- What proportion of students scored greater than 600?
- What proportion of students scored between 600 and 650?
- What score is necessary to be in the top 5% of student test takers?
- 60% of students will score above x on the exam. What is x?

- In a recent year, 10th grade students took a standardized English language exam. The mean score was 572 and the standard deviation was 51, i.e.,
**Problem 2**- Repeat each question in Problem 1 using a different normal distribution of scores:
**N(505,110)**.- What proportion of students scored less than 600?
- What proportion of students scored greater than 600?
- What proportion of students scored between 600 and 650?
- What score is necessary to be in the top 5% of student test takers?
- 60% of students will score above x on the exam. What is x?

- Repeat each question in Problem 1 using a different normal distribution of scores:

Study:

- Read Text pp. 62-68

- 4 years ago
- f19-busad265
- Justin

Review:

- Quiz 2
- Standard Deviation
**Exam 1 on Wed Sep 18**

Presentation:

- Normal Curves
- Density Curves
- Height of curve indicates proportion of values
- Area under the curve = 1.0
- Any sub-area under the curve is then a proportion (% of values)

- Normal Curves
- A special case of density curves
- Bell shaped and symmetrical
- Mean and Standard deviation
- 68 – 95 – 99.7 Rule
- Video (until 4:30)
- Demonstrate with student height data

- Density Curves
- Standard Normal Distribution
- Mean = 0
- Standard Deviation = 1
- Calculating Z-Scores
- (x – mean)/std dev
- Example (p. 61)
- Young women heights normally distributed
- Mean = 64.5 in
- Standard Deviation = 2.5 in
- Z-Score for woman 68 inches tall
- Z = (68 – 64.5)/2.5 = 1.4

- Z-Score for woman 60 inches tall
- Z = (60 – 64.5)/2.5 = -1.8

- Calculating proportions/probabilities with Z-scores

Activity:

**Problem 1.** The distribution of heights of young women (18 – 24 years old) is approximately normal with mean = 64.5 inches and standard deviation = 2.5 inches.

- Draw a normal curve with a horizontal axis. Label mean.
- What is the z-score for a 20-yr-old woman who is 6 ft tall? Label point.
- Between what two values do the heights of the central 95% of young women lie? Shade this area.
- What % of young women are more than two standard deviations taller than the mean?

**Problem 2.** There are two national college-entrance examinations, the SAT and the ACT. Scores on individual SAT exams are approximately normal with mean = 500 and standard deviation=100. Scores on the ACT exams are approximately normal with mean = 18 and standard deviation = 6.

- Julie’s SAT Math score is 630. John’s ACT Math score is 22. Calculate the standardized Z-scores for both.
- Assuming that both tests measure the same kind of ability, who has the higher score?
- What percent of all SAT scores are above 600?

**Problem 3.** Find the percentage of observations from a standard normal distribution that satisfy the following. Also, draw a normal curve and shade the corresponding area under the curve.

- z < −1
- z < 1
- z > -2
- z > 2
- −1 < z < 2
- -2 < z < 0

Assignment:

- Text Ch. 1 pp. 61-64

- 4 years ago
- f19-busad265
- Justin

Review:

- Measures of Center
- Boxplots
- Alternative for boxplots: http://www.imathas.com/stattools/boxplot.html

- Attendance

Presentation:

- Demonstrate calculation
- Find the variance and the standard deviation for the following (n=10) exam scores: 80 73 92 85 75 98 93 55 80 90
- Demonstrate in Google Sheets

- Video

Activity:

**Problem 1.** Below are the number of home runs that Babe Ruth hit in each of his 15 years with the New York Yankees, 1920 – 1934. Calculate the mean and standard deviation.**54 59 35 41 46 25 47 60 54 46 49 46 41 34 22 **

**Problem 2.** Six 9th-grade students and six 12th-grade students were asked: how many movies have you seen this month? See their responses below. Calculate the mean and standard deviation for each data set. Which is more spread out, the 9th-grade or 12th-grade data?

9th-grade: **5, 1, 2, 5, 3, 8**

12th-grade: **4, 2, 0, 2, 3, 1**

Assignment:

- Repeat Problems 1 and 2 (above) using Sheets
- Using the Student Height Data, calculate mean and standard deviation in Sheets
- Text Ch. 1, p. 40-44

- 4 years ago
- f19-busad265
- Justin

Review:

- Quiz 1
- Data Distributions
- Stemplots
- Histograms

- Attendance (use Quiz)

Presentation:

- Measures of Center
**Mean**- Same as Average
- Sum of values divided by count, or ∑x/n
- n = total number of observations/measurements/values
- Example with height data

**Median**- Center value within
**ordered sequence**of values - Same as 50th Percentile
- Position = 0.50*n
- n = total number of observations
- round to the nearest whole number
- alternative for small (n<30) data sets = (n+1)/2

- Example with height data

- Center value within
- Video: Measures of Center

- Percentiles and Boxplots
**Percentiles**- To find the xth percentile
- calculate x/100 * n (rounded to the nearest integer or take average of two values on either side)
- result is the position of the value in an ordered (smallest to largest) data set
- 25th percentile = 25/100 * n
- 50th percentile = 50/100 * n = Median
- 75th percentile = 75/100 * n
- Example with Female height data
- 152, 157, 160, 165(2), 168, 170(3), 173(2), 180

**Boxplots**- Five number summary
- 25th Percentile = Q1
- 50th Percentile = Q2 = Median
- 75th Percentile = Q3
- Minimum value
- Maximum value
- Range = Max – Min
- Interquartile Range (IQR) = Q3 – Q1
- Example with Male height data
- 160, 168, 170(2), 173(3), 175(3), 177, 178(15), 180(4), 183(5), 185(4), 188(5), 191(4), 193, 196(2), 203

- Video: Boxplots
- Examples

Activity:

**Problem 1.**

Here are the starting salaries, in thousands of dollars, offered to 20 students who earned bachelor’s degrees in computer science in 2011.*63 56 66 77 50 53 78 55 90 65 64 69 59 76 48 54 49 68 51 50*

a. Make a stemplot.

b. Find the median, mean and mode.

c. Find the five-number summary.

d. Make a boxplot.

e. Compute the range and interquartile range (IQR).

**Problem 2.**

A consumer testing lab measured calories per hot dog in 20 brands of beef hot dogs. Here are the results:* 186 181 176 149 184 190 158 139 175 148 152 111 141 153 190 157 131 149 135 132*a. Make a stemplot.

b. Find the median, mean and mode.

c. Find the five-number summary.

d. Make a boxplot.

e. Compute the range and interquartile range (IQR).

*These problem descriptions (#1 and #2) are from “Against All Odds”, modified slightly and copied here for convenience.*

**Problem 3.**

Use the MPG data for top selling midsize cars in the US and European markets from Lesson 1.

a. Find the five-number summaries.

b. Produce 2 boxplots, one for each market, and * put them both on the same axes* to facilitate comparison.

Assignment:

- Text: Ch. 1 p. 30-38

- 5 years ago
- f19-busad265
- Justin

Review:

- Attendance
- Intro to Statistics
- Syllabus
- Textbook
- Assessment Answers
- a, d, e, d, b, e, d, e, b, e

Presentation:

- Data Distributions
- The “shape” of the data
- Distribution of Exam Scores
- Types of distributions
- Skewed, bi-modal, u-shaped, uniform, etc

- Theoretical Probability Distributions
- Visualize the distribution
- Picture is worth a thousand words
- Not much training necessary to look at a data graphic
- Improved approach for “
**patterns**” and “**participation**“ - Use stemplots for small datasets
- Use histograms for large datasets

- Unit 2: Stemplots
- Video (0:45-2:00; 6:00-11:00)
- Demonstrate stemplot construction
- Female heights (cm)
- 152, 157, 160, 165, 165, 168, 170, 170, 170, 173, 173, 180
- Rules
- Keep rows and columns neatly aligned
- Don’t use commas
- Display gaps in data with empty space

- Unit 3: Histograms
- Video (0:50-4:00)
- Demonstrate histogram construction
- Student Height Data (Sheets)

Activity:

- Using the vehicle mpg data (below), create
**three stemplots**- Top Selling Midsize Cars in the US
- Top Selling Midsize Cars in Europe
- Back to back comparison – US vs Europe

- Using the same vehicle mpg data (below), create
**two histograms**- Top Selling Midsize Cars in the US
- Top Selling Midsize Cars in Europe

Study:

- Text: Ch. 1, p. 9-15

Activity Data:

Top Selling Midsize Cars in the US – MPG

- Toyota Camry – 32
- Honda Accord – 33
- Nissan Altima – 30
- Subaru Outback – 29
- Ford Fusion – 27
- Chevy Malibu – 26
- Kia Optima – 27
- Volkswagen Passat – 29
- Subaru Legacy – 29

Top Selling Midsize Cars in the Europe – MPG

- Volkswagen Passat – 35
- Skoda Superb – 66
- Opex Insignia – 53
- Ford Mondeo – 48
- Renault Talisman – 35
- Toyota Avensis – 63
- Mazda 6 – 30
- Peugeot 508 – 62
- Kia Optima – 58
- Hyundai i40 – 67

- 5 years ago
- f19-busad265
- Justin

Presentation:

- Attendance
- Syllabus (PDF)
- Course Overview
- Bookmark this course page
- Classroom activities
- Weekly Quiz
- Grading
- Exams and make-up

- Video:
- Textbook:

Activity:

- Complete survey + assessment

Study:

- Review Syllabus
- Text: Ch. 1, p. 1-9