1. Foundational Questions
    1. Definitions
    2. Sampling Distribution Characteristics I
    3. Sampling Distribution Characteristics II
    4. Sampling Distribution Characteristics III
    5. Accuracy and Precision

 

 

Definitions

You can click on each question to see an answer. Click on it again to close the answer.

What type of distribution is blood serum level for every individual in a population?
Population Distribution
What type of distribution is mean cholesterol level computed from all possible samples of n = 15 patients for a clinic?
Sampling Distribution
What type of distribution is water discharge amounts for Bay City Creek for every day in 2005 assuming that all days in 2005 was the population of interest?
Population Distribution
What type of distribution is the proportion of days where the water discharge from Bay City Creek is near negligible calculated from all samples of n = 30 days.
Sampling Distribution (the proportion is a statistics computed from a sample of 30 day)
On average, the mean length of n = 30 cicadas is 2.9 mm away from the overall average. Is this a standard deviation or a standard error?
SE (because it is refering to a mean from samples)
On average, the number of litter items found along the Escarpment Trail in the Porcupine Mountains on a single day is 12 items different than the overall mean. Is this a standard deviation or a standard error?
SD (because it is referring to an individual (a single day) and not a sample of individuals)

Sampling Distribution Characteristics I

Assume that the population distribution is ~N(100,20) and you take samples of n=50.

  1. What shape would you expect the sampling distribution of the sample means to be?
  2. What do you expect the center of the sampling distribution of the sample means to equal?
  3. What do you expect the standard deviation of the sampling distribution of the sample means to equal?
  4. What do you expect the standard error of x̄ to equal?

See answer here

Sampling Distribution Characteristics II

Assume that the population distribution is skewed to the right with μ=500 and σ=60. Further suppose that samples of n=100 are taken.

  1. What shape would you expect the sampling distribution of the sample means to be?
  2. What do you expect the center of the sampling distribution of the sample means to equal?
  3. What do you expect the standard deviation of the sampling distribution of the means to equal?
  4. What do you expect the standard error of x̄ to equal?

See answer here

Sampling Distribution Characteristics III

Assume that the population distribution is slightly skewed to the right with μ=500 and σ=60. Further suppose that samples of n=20 are taken.

  1. What shape would you expect the sampling distribution of the sample means to be?
  2. What do you expect the center of the sampling distribution of the sample means to equal?
  3. What do you expect the standard deviation of the sampling distribution of the means to equal?
  4. What do you expect the standard error of x̄ to equal?

See answer here

Accuracy and Precision

Suppose that it is known that a population has μ=10. Use this to answer the questions below.

  1. Which is more accurate – four samples with means of 9,10,11, and 9 or means of 6,8,7, and 9?
  2. Which is more accurate – four samples with means of 6,14,8, and 12 or means of 8,7,9, and 8?
  3. Which is more precise – four samples with means of 7,14,8, and 11 or means of 7,7,9, and 8?
  4. How would you judge the accuracy and precision of four samples with means of 2,8,12, and 18?
  5. How would you judge the accuracy and precision of four samples with means of 9,10,11, and 10?
  6. How would you judge the accuracy and precision of four samples with means of 1,7,8, and 19?

See answer here