Review Feb 27

The population distribution of variable Y is right skewed. What will be the distribution of a series of sample means with a large sample size?

• Right skewed

• Nearly uniform

• Uniform

• Approximately normal

State whether you would use a population distribution or a sampling distribution to solve this problem:
The weights of the eggs produced by a certain breed of hen are normally distributed with mean 65 grams and standard deviation of 5 grams.
What is the probability that one egg selected at random from a hen house will weigh more than 68 grams?

• Population distribution

• Sampling distribution

State whether you would use a population distribution or a sampling distribution to solve this problem:
The weights of the eggs produced by a certain breed of hen are normally distributed with mean 65 grams and standard deviation of 5 grams.
What is the probability that the average weight of a dozen eggs selected at random will be more than 68 grams? 

• Population distribution

• Sampling distribution

What is Pr{Z < 0.53}?

• 0.7019

• 0.077

• 0.6915

• 0.2981

What is Pr{Z > 0.49}?

• 0.6879

• 0.6554

• N/A

• 0.3121

For variable Y, μ = 9.2 and σ = 2.1. What is Pr{Y < 10}?

• 0.6844

• 0.6517

• N/A

• 0.6483

Which of these is a FALSE statement about how standard deviation differs from standard error?

• SD measures the spread of data within a sample. SE measures variable across multiple samples from a population.

• SD can be used to show natural variability (noise). SE can be used to show measurement error.

• SD is primarily a descriptive statistic. SE is primarily used in hypothesis testing.

• SD is useful to see the variability in your dataset. SE is useful to tell how well your estimates describe the population.