Download BUAL 2650 CHEN YAN Q&A LATEST 2024/2025 | 100% PASS and more Exams Business Economics in PDF only on Docsity!
BUAL 2650 CHEN YAN
Q&A LATEST 2024/2025 | 100% PASS
"Analytics - Correct Answer a process that examines data using a variety of statistical tools and
involves the discovery, interpretation, and application of meaningful patterns toward effective decisions making in the workplace"
"Statistics - Correct Answer branch of mathematics that studies methods for the calculation of
probabilities and provides tools for prediction and forecasting models"
"Business User - Correct Answer person who takes data to make decisions based on their jobs and also
interprets data"
"Data Scientist - Correct Answer a person skilled in data inference, algorithm development and
technology in order to solve complex problems."
"Scatter Plot (what relationship does this image show) - Correct Answer The relation between %Fat
and BMI is positive because it is going up. It is weaker towards the higher on the curve however very strong near the bottom of the curve around point (20,20)" "This scatter plot shows the relationship between an iPhone app's price and the quantity sold at different prices in thousands. A line of best fit is given.
Question: What's the relationship between app's price and quantity sold? - Correct Answer This graph
shows a negative, strong relationship between Apple App's price and Quantity Sold."
"Interpret a correlation coefficient of -0.96 (R) - Correct Answer The correlation coefficient is the
distance away from the points on the graph. Or the variability. This shows that these two items have a very high, negative correlation to one another and affect each other strongly." "The coefficient of determination (r^2) is 0.92. Please interpret it. (of apple's app price and quantity
sold) - Correct Answer This means that there is a 92% chance of variability in Apple App's Price and
Quantity Sold. This is also considered strong because it is >.70." "In a study of 6- to 11-year-old elementary school children, researchers find a strong positive association between reading level and weight (i.e. Heavier children have higher reading levels). Please identify the
independent variable (aka explanatory variable) and dependent variable (aka response variable). -
Correct Answer Independant Variable- Weight
Dependant Variable - Reading Level"
"In a study of 6- to 11-year-old elementary school children, researchers find a strong positive association between reading level and weight (i.e. Heavier children have higher reading levels). Please identify a
potential lurking variable and explain why. - Correct Answer Heavier children eat more meaning they
have more money, which means they have a better education. Or the heavier kids have more free time than not as heavy kids, due to physical activity, causing them to have more practice time reading."
"Time Series (Components) - Correct Answer trend, cyclical, seasonal, irregular"
"Trend - Correct Answer long run growth, or decline"
"Cycle - Correct Answer long-run up and down fluctuation around the trend level"
"Seasonal - Correct Answer Regular periodic up and down movements that repeat within the calendar
year"
"Irregular - Correct Answer Erratic very short-run movements that follow no regular pattern"
"Trend - Correct Answer -sales decreasing and increasing over time
-sales is the dependent variable -time is the independent variable -can use quadratic regression"
"Seven steps of business analytic process - Correct Answer 1. Define the business problem
- Manage Data
- Descriptive Analytics
- Predictive Analytics
- Prescriptive Analytics
- Make actionable recommendations
- Ask the next questions" "Simple linear regression is how many variables?
What do we use for simple linear in terms of r square, how about multiple linear? - Correct Answer a.
b. For simple linear regression we use regular r square, and for multiple, we use adjusted r square, the adjusted value will help us adjust our variables and their values."
"Significance - Correct Answer Use significant F for the whole model
Who p-value for individual variable"
"F formula - Correct Answer MSR/MSE"
"What do we call situations when independent variables are highly correlated? - Correct Answer
Multicollinearity"
"Which of the following propositions describes an existing theory or belief? - Correct Answer null
hypothesis" "A Tufts University study finds that 40% of 12th grade females feel they are overweight. To determine
whether this percent is lower for college age females, the correct alternative hypothesis is _________. -
Correct Answer p<0.4"
"A Tufts University study finds that 40% of 12th grade females feel they are overweight. To determine
whether this percent is higher for college age females, the correct alternative hypothesis is _________. -
Correct Answer p>0.4"
"A Tufts University study finds that 40% of 12th grade females feel they are overweight. To determine whether this percent is the same as that of college age females, the correct alternative hypothesis is
_________. - Correct Answer p≠0.4"
"Which is NOT an Assumption for Logistic Regression? - Correct Answer Continuous or Quantitative"
"What is the confidence level when the level of significance is 0.05? - Correct Answer 95%"
"A two-sample test for means was conducted to determine if he completion time for continuing education programs for nurses differed when costs are paid by employers (Yes) versus when individuals paid out of his or her own funds (No).
If the alternative hypothesis is μYes- μNo > 0, it leads to _____________ test. - Correct Answer Upper-
tailed"
"Interpret the odds ratio estimates for Test 1. - Correct Answer For every one point increase in the
score on test 1 when the score on test 2 stays constant, we estimate that a potential employee's odds of success increase by 62 percent."
"What are the 6 steps of hypothesis testing? - Correct Answer 1. State the null and alternative
hypotheses
- State level of significance
- Collect and test statistic
- Calculate P-vale
- Apply Decision rule, if p is less than or equal to A, reject H0; otherwise do not reject H
- Interpret the results" "Who would be more likely to respond, a 20-year-old customer who has recently purchased another
item, or a 50-year-old customer who has not purchased in a year? Why? - Correct Answer A 50-year-
old customer who has not purchased in a year is more likely to respond. This is because based on our fitted logistic regression model age is increasing and positive and this is the same for days since last purchased. Therefore, the older you are and the more days since the last purchase, the more likely you are to respond."
"________ is a collection of techniques that seek to group or segment a collection of objects or observations into subsets, such that those within each subset are more closely related to one another
than objects assigned to different subsets. - Correct Answer Cluster analysis"
"Which of the following is the first stage of joining clusters in agglomerative hierarchical clustering? -
Correct Answer by joining two clusters that are closest to each other"
"Divisive clustering method is different from agglomerative clustering methods in that divisive clustering
methods ________. - Correct Answer separate n objects successively into finer groupings"
"If the Euclidean distance were to be represented in a right triangle, which of the following would be
considered the distance between two objects of a cluster? - Correct Answer the hypotenuse"
"In the ________ method, the distance between groups is defined as the distance between the closest
pair of objects, where only pairs consisting of one object from each group are considered. - Correct
Answer single linkage clustering"
"Which of the following is an example of time series problem?
- Estimating number of hotel rooms booking in next 6 months.
- Estimating the total sales in next 3 years of an insurance company.
3. Estimating the number of calls for the next one week. - Correct Answer 1,2 and 3"
"In time series model, the number of dummy variables required if a categorical variable has k levels is: -
Correct Answer k−1"
"Is time (T) a dependent variable or independent variable in a time series plot? - Correct Answer
independent variable" "Spam filtering for e-mails can be seen as an example of which of the following types of approaches of
data mining? - Correct Answer classification"
"CLuster Merging - Correct Answer Merge the clusters that are the closest together, this is denoted by
the smallest number in the matrix" "Finish the following equation to model time series data with a linear trend. (Fill in the blank)
y(t)= B(0) + B(1) * ____ + E(t) - Correct Answer t"
"Euclidean Distance Formula (x(1), x(2)) (y(1), y (2)) - Correct Answer √(x(1) - y (1))^2 + x(2) - y (2))^2"
"1. Explain how to use this information to draw a conclusion if the null hypothesis is Clearly state the p- value and your conclusion.
