the power of statistics coursera weekly challenge 4 answers

Test your knowledge: Introduction to confidence Intervals

1. Which of the following statements describes an interval estimate?

  • An interval estimate uses a single value to estimate a population parameter.
  • An interval estimate uses a range of values to estimate a sample statistic.
  • An interval estimate uses a range of values to estimate a population parameter.
  • An interval estimate uses a single value to estimate a sample statistic.

2. What is the maximum expected difference between a population parameter and a sample estimate?

  • Margin of error 
  • Standard deviation
  • Confidence level
  • Range 

3. A 95% confidence interval means that 95% of all the data values in the dataset fall within the interval.

  • True
  • False

Test your knowledge: Construct confidence intervals

4. After identifying a sample statistic, what is the proper order of the next three steps of constructing a confidence interval?

  • Choose a confidence level, find the margin of error, and calculate the interval
  • Find the margin of error, choose a confidence level, and calculate the interval 
  • Choose a confidence level, calculate the interval, and find the margin of error.
  • Find the margin of error, calculate the interval, and choose a confidence level

5. A data professional is working for an online retail company. Their manager asks them to estimate the mean time customers spend on the company’s website. They construct a confidence interval based on a sample mean of 50 seconds and a margin of error of 4 seconds. What is the interval?

  • [54, 46]
  • [50, 54]
  • [46, 50]
  • [46, 54]

6. What happens as a sample size gets larger? Select all that apply.

  • The confidence interval narrows. 
  • The margin of error decreases.
  • The margin of error increases.
  • The confidence interval widens.

Test your knowledge: Work with confidence intervals in Python

7. What Python function enables a data professional to compute the standard deviation term in the sample standard error of a mean?

  • pandas.DataFrame.mode()
  • pandas.DataFrame.median()
  • pandas.DataFrame.std()
  • pandas.DataFrame.hist()

8. A data professional is constructing a confidence interval of the sample mean using the function scipy.stats.norm.interval(). What arguments should they specify? Select all that apply.

  • Scale, which they set to the sample standard error
  • Loc, which they set to the sample mean
  • Iqr, which they set to the interquartile range
  • Alpha, which they set to the confidence level

Shuffle Q/A 1

Weekly challenge 4

9. What is a key difference between a point estimate and an interval estimate?

  • A point estimate uses a range of values to estimate a population parameter; an interval estimate uses a single value to estimate a population parameter.
  • A point estimate uses a single value to estimate a population parameter; an interval estimate uses a range of values to estimate a population parameter.
  • A point estimate uses a single value to estimate a sample statistic; an interval estimate uses a range of values to estimate a sample statistic. 
  • A point estimate uses a range of values to estimate a sample statistic; an interval estimate uses a single value to estimate a sample statistic.

10. Fill in the blank: The _____ represents the maximum expected difference between a population parameter and a sample estimate.

  • margin of error
  • sampling distribution
  • sample statistic
  • confidence level
Next

Leave a Reply