Data & Stats 7.1-7.4 Test

Do you think the school is doing enough to provide student parking? Of the 136 people who responded, 79% said "No". The number 79% is a: (a)  

• Statistic
• Parameter
• Sample
• Population

When a newspaper poll uses a method that is BIASED, it means that repeated polls...

• ...tend to miss the truth about the population in the same direction

• ...would give results that are very different from each other

• ...give results that would not yield a normal distribution

• ...would give results that are very similar to each other

"Do you favor a law banning lawn mowing after 8 pm?" Suppose that 35% of all citizens favor the law. If we took a very large number of SRSs of size n = 250 from this population, the sampling distribution of the sample proportion [p hat] would have which of the following characteristics?

• Mean = 0.35

  SD = 0.0009

  Shape: unknown

• Mean = 0.35

  SD = 0.0009

  Shape: Approx. Normal

• Mean = 0.35

  SD = 0.022

  Shape: unknown

• Mean = 0.35

  SD = 0.022

  Shape: Approx. Normal

"Do you favor a law banning lawn mowing after 8 pm?" If 35% of all citizens favor the law, and we take a very large number of SRSs of an increased size n = 600 rather than n = 150 from this population, how would it affect the estimate?

• reduce the bias of the estimate

• increase the bias of the estimate

• reduce the variability of the estimate

• increase the variability of the estimate

Which of the following best describes a sampling distribution?

The distribution of...

• ...a random sample of values of a sample statistic found in less than 10% of simulated samples of size n from the population

• ...values taken by a statistic in all possible samples of the same size from the same population

• ...parameter values in all possible samples of size n

• ...all values in a single random sample selected from the population

• ...is approximately normal with mean 60 and standard deviation 10

• is approximately normal with mean 60 and standard deviation 2

• has an unknown shape with mean 60 and standard deviation 1.414

• ...has an unknown shape with mean 60 and standard deviation 2

You are sampling from a distribution that is strongly skewed to the left. Which of the following statements about the shape of the sampling distribution of the sample mean is true?

• Regardless of the sample size, the shape of the sampling distribution will be the same as the shape of the population distribution.

At a high school, 29% of students are freshmen. Let (p-hat) = the proportion of students that are freshmen in a random sample of 25 students from the school. Which of the following statements about the mean and standard deviation of the sampling distribution of (p-hat) is true?

The figures below show approximate sampling distributions of 4 different statistics intended to estimate the same parameter. The true value of the parameter is 12. Which statistic has the smallest bias and the smallest variability?

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• 
• 
• 

The basketball team has four players who can play the center position. Their heights (in inches) are 78, 80, 77, and 80.

List all 6 possible SRSs of size n = 2, calculate the mean height for each sample.