Inferential Statistics Week 1 Quiz Answer

Inferential Statistics Week 1 Quiz Answer

Inferential Statistics Week 1 Quiz Answer


In this article, i am gone to Share Inferential Statistics Week 1 Quiz Answer Coursera.



Week 1 Quiz 

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Question 1)

Researchers studying anthropometry collected body girth measurements and skeletal diameter measurements, as well as age, weight, height and gender, for 507 physically active individuals. The histogram below shows the sample distribution of heights in centimeters, and the table shows sample statistics calculated based on this sample. Which of the following is not necessarily true?





  • The sample mean is 171.1 cm.
  • The sample median is 170.3 cm.
  • The point estimate for the population mean is 171.1 cm.
  • The population mean is 171.1 cm.




Question 2)

Researchers studying anthropometry collected various body and skeletal measurements for 507 physically active individuals. The histogram below shows the sample distribution of heights in centimeters. If the 507 individuals are a simple random sample- and let's assume they are - then the sample mean is a point estimate for the mean height of all active individuals. What measure do we use to quantify the variability of such an estimate? Compute this quantity using the data from this sample and choose the best answer below.




  • standard deviation = 0.417
  • mean squared error = 0.105
  • standard error = 0.417
  • standard deviation = 0.019
  • standard error = 0.019




Question 3)

For the standard deviation 𝝈 or s and the standard error SE, which of the following is the correct set of descriptions?


  • s: variability in sample data
  • SE: variability in point estimates from different samples of the same size and from same population
  • 𝝈 variability in population data


  • 𝝈 variability in sample data
  • SE: variability in point estimates from different samples of the same size and from same population
  • s: variability in population data


  • SE: variability in sample data
  • 𝝈: variability in population data
  • s: variability in point estimates from different samples of the same size and from same population


  • 𝝈: variability in sample data
  • s: variability in point estimates from different samples of the same size and from same population
  • SE: variability in population data




Question 4)

Suppose you took a large number of random samples of size n from a large population and calculated the mean of each sample. Then suppose you plotted the distribution of your sample means in a histogram. Now consider the following possible attributes of your collected data and the population from which they were sampled. For which of the following sets of attributes would you not expect your histogram of your sample means to follow a nearly normal distribution?

  • n= 10. The population distribution is unknown, but the distribution of data in each sample is heavily skewed.
  • n = 120. The population distribution is unknown, but the distribution of data in each sample is slightly skewed.
  • n = 120. The population distribution is slightly skewed.
  • n = 20. The population distribution is nearly normal.




Question 4)

The General Social Survey (GSS) is a sociological Survey used to collect data on demographic characteristics and attitudes of residents of the United States. In 2010, the survey collected responses from over a thousand US residents. The survey is conducted face to-face with an in-person interview of a randomly selected sample of adults. One of the questions on the survey is "For how many days during the past 30 days was your mental health, which includes stress, depression, and problems with emotions, not good?

Based on responses from 1,151 US residents, the survey reported a 95% confidence interval of 3.40 to 4.24 days in 2010. Given this information, which of the following statements would be most appropriate to make regarding the true average number of days of "not good" mental health in 2010 for US residents?


  • For all US residents in 2010, based on this 95% confidence interval, we would reject a null hypothesis stating that the true average number of days of "not good" mental health is 5 days.
  • There is not sufficient information to calculate the margin of error of this confidence interval.
  • For these 1,151 residents in 2010, we are 95% confident that the average number of days of "not good" mental health is between 3.40 and 4.24 days.
  • For all US residents in 2010, there is a 95% probability that the true average number of days of "not good" mental health is between 3.40 and 4.24 days.





Question 6)
Suppose we collected a sample of size n = 100 from some population and used the data to calculate a 95% confidence interval for the population mean. Now suppose we are going to increase the sample size to n = 300. Keeping all else constant, which of the following would we expect to occur as a result of increasing the sample size?

1. The standard error would decrease. 
2. Width of the 95% confidence interval would increase. 
3. The margin of error would decrease.


  • II and III
  • I and III
  • I and II
  • I, II, and III
  • None





Question 7)
Researchers investigating characteristics of gifted children collected data from schools in a large city on a random sample of thirty-six children who were identified as gifted children soon after they reached the age of four. The following histogram shows the distribution of the ages in months) at which these children first counted to 10 successfully. Also provided are some sample statistics.

Calculate a 90% confidence interval for the average age at which gifted children first count to 10 successfully. Choose the closest answer.





  • (30.12, 31.26)
  • (30.49, 30.89)
  • (29.50, 31.88)
  • (29.28, 32.10)








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