01. A hypothesis test sometimes rejects the null hypothesis even if the true value of the population parameter is the same as the value in the null hypothesis.
This type of result is known as:
a) A Type I Error
b) A Type II Error
c) A correct inference
d) The confidence level of the inference
02. The sales of a grocery store had an average of $8,000 per day. The store introduced several advertising campaigns in order to increase sales.
To determine whether the advertising campaigns have been effective in increasing sales, a sample of 64 days of sales was selected, and the sample mean was $8,300 per day.
The correct null and alternative hypotheses to test whether there has been a significant increase are:
a) Null: Sample mean is 8,000; Alternative: Sample mean is greater than or equal to 8,000.
b) Null: Sample mean is 8,000; Alternative: Sample mean is greater than 8,000.
c) Null: Population mean is 8,000; Alternative: Population mean is greater than or equal to 8,000.
d) Null: Population mean is 8,000; Alternative: Population mean is greater than 8,000.
03. A data analyst has been asked to create an ad-hoc sales report for the Chief Executive Officer (CEO). Which of the following should be included in the report?
a) The sales representatives' home addresses
b) Line-item SKU numbers
c) YTD total sales
d) The customers' first and last names
04. Which of the following can be used to translate data into another form so it can only be read by a user who has a key or a password?
a) Data encryption
b) Data transmission
c) Data protection
d) Data masking
05. Q3 2020 has just ended, and now a data analyst needs to create an ad-hoc sales report that demonstrates how well the Q3 2020 promotion went versus last year's Q3 promotion.
Which of the following date parameters should the analyst use?
a) 2019 vs. YTD 2020
b) Q3 2019 vs. Q3 2020
c) YTD 2019 vs. YTD 2020
d) Q4 2019 vs. Q3 2020
06. What Python library provides data analysts with access to tools that allow them to better structure data?
07. Melinda is analyzing a movie dataset, where individual films have a star rating between 1 and 5. What type of data is this?
a) Nonparametric data
b) Redundant data
c) Duplicate data
d) Data outlier
08. Which of the following is an example of a discrete data type?
a) 8in (20cm)
b) 5 kids
c) 2.5mi (4km)
d) 10.7lbs (4.9kg)
09. George wants to integrate data from his city's open data portal. Reading the website, he sees that he can download the data he wants as a CSV file. After manually downloading the file, he writes the code to transform the data and load it into his database.
Presuming the data changes once a month, what can George do to ensure he has the most up-to-date data from the city?
Choose the best answer.
a) Manually check the city's website every day.
b) Contact the city and encourage the development of an API.
c) Automate the process that downloads, transforms, and uploads the CSV file.
d) Nothing, George has already successfully loaded the data.
10. Which of the following contains alphanumeric values?