The Central Limit Theorem
50 questions available
Questions
According to the introduction of Chapter 7, what is the most important conclusion of the Central Limit Theorem regarding the distribution of sample means?
View answer and explanationWhat is the term for the standard deviation of the distribution of the sample means?
View answer and explanationAccording to the Central Limit Theorem, what is the mean of the theoretical sampling distribution of the means (μx̄)?
View answer and explanationHow does increasing the sample size (n) affect the standard deviation of the sampling distribution of means?
View answer and explanationWhen is it appropriate to use the Finite Population Correction Factor?
View answer and explanationA population has a mean of 48 and a standard deviation of 5. If it is sampled repeatedly with samples of size 36, what is the mean and standard deviation of the sample means?
View answer and explanationThe Central Limit Theorem is described as a 'theorem'. What does this imply?
View answer and explanationA researcher is studying a population with a very skewed distribution. What does the Central Limit Theorem say about the sampling distribution of the means if the sample size is large enough?
View answer and explanationFor the Central Limit Theorem for Proportions, the underlying distribution of the random variable X (number of successes) is which of the following?
View answer and explanationA population has a mean of 90 and a standard deviation of 6. If it is sampled repeatedly with samples of size 64, what are the mean and standard deviation of the sample means?
View answer and explanationWhat is the primary reason that one samples a population instead of measuring the entire population?
View answer and explanationIn the context of the Central Limit Theorem, what does the Law of Large Numbers state?
View answer and explanationA fishing boat has 1,000 fish on board. The average weight is 120 pounds with a standard deviation of 6.0 pounds. If a sample of 50 fish is taken, what is the standard error of the mean?
View answer and explanationIn a town, 37 percent of people have a specific characteristic. If random samples of 30 people are repeatedly taken, what is the expected value of the mean of the sampling distribution of sample proportions?
View answer and explanationFor the CLT for proportions to apply, and for the binomial distribution to be approximated by the normal distribution, the sample size n must be large enough such that:
View answer and explanationWhat does the standardizing formula Z = (x̄ - μ) / (σ/√n) actually compute?
View answer and explanationA company has 800 employees with an average number of workdays between absence for illness of 123 and a standard deviation of 14 days. A sample of 50 employees is examined. Is the Finite Population Correction Factor needed for this problem?
View answer and explanationFigure 7.8 on page 322 shows three sampling distributions with sample sizes of 10, 30, and 50. What is the primary visual difference between the distribution for n=10 and the distribution for n=50?
View answer and explanationA game is played repeatedly where a player wins one-fifth of the time. If samples of 40 games are taken, what is the standard deviation of the sampling distribution of sample proportions?
View answer and explanationThe Central Limit Theorem for Proportions is built upon the idea that the binomial distribution can be approximated by which other distribution?
View answer and explanationWhy is the sampling distribution of the means considered a 'theoretical distribution'?
View answer and explanationA population has a mean of 25 and a standard deviation of 2. If it is sampled repeatedly with samples of size 49, what is the mean and standard deviation of the sample means?
View answer and explanationWhat is the key takeaway from Figure 7.9 on page 323, which shows a narrow and a wide sampling distribution?
View answer and explanationA manufacturer produces 25-pound lifting weights. The lowest actual weight is 24 pounds, and the highest is 26 pounds, with a uniform distribution. What is the mean (μ) and standard deviation (σ) for the weights of one 25-pound lifting weight?
View answer and explanationUsing the information from the previous question (μ = 25, σ = 0.5774), what is the distribution for the mean weight of 100 25-pound lifting weights?
View answer and explanationWhat is the key difference between the formula for the standard error of the mean when using the Finite Population Correction Factor versus when not using it?
View answer and explanationA population has a mean of 17 and a standard deviation of 0.2. If it is sampled repeatedly with samples of size 16, what is the expected value and standard deviation of the sample means?
View answer and explanationA virus attacks one in three of the people exposed to it. If samples of 70 people are taken, what is the standard deviation of the sampling distribution of sample proportions?
View answer and explanationIn the context of Chapter 7, what is the practical significance of the sampling distribution of the means being normally distributed?
View answer and explanationIn Example 7.2, with 3,000 orders and a sample of 360, the Finite Population Correction Factor is used. Why was it necessary?
View answer and explanationThe length of time a smartphone battery lasts follows an exponential distribution with a mean of ten months. A sample of 64 smartphones is taken. What is the standard deviation of the individual battery lives?
View answer and explanationFrom the previous question, a sample of 64 smartphones is taken from a population with μ=10 and σ=10. What is the distribution for the mean length of time the 64 batteries last?
View answer and explanationThe sampling distribution of a parameter is best described as:
View answer and explanationA uniform distribution has a minimum of six and a maximum of ten. A sample of 50 is taken. What is the approximate distribution of the sum of the 50 values (Σx)?
View answer and explanationThe formula for the Finite Population Correction Factor is √((N-n)/(N-1)). Why is N-1 used in the denominator instead of N?
View answer and explanationIf a population is already normally distributed, what is the minimum sample size needed for the sampling distribution of the means to also be considered normal?
View answer and explanationWhat is the expected value of the sample proportion, E(p')?
View answer and explanationAn experimental garden has 500 sunflower plants with an average height of 9.3 feet and a standard deviation of 0.5 foot. If a sample of 60 plants is taken, what is the probability the sample will have an average height within 0.1 foot of the true mean?
View answer and explanationWhich statement best describes the relationship between the Central Limit Theorem and the Law of Large Numbers?
View answer and explanationWhat is the primary trade-off discussed in the text regarding sampling distributions?
View answer and explanationA population has a mean of 14 and a standard deviation of 5. If it is sampled repeatedly with samples of size 60, what is the expected value and standard deviation of the sample means?
View answer and explanationIf you are analyzing a sampling distribution of proportions, and the population proportion 'p' is unknown, what value is commonly used for p to ensure a large enough sample size is calculated?
View answer and explanationWhat is the conclusion of the Central Limit Theorem regarding the underlying distribution of the population data?
View answer and explanationFor a population of 2,000 trucks with an average weight of 20 tons and a standard deviation of 2 tons, a sample of 50 trucks is taken. What is the approximate probability the sample will have an average weight within 0.5 ton of the population mean?
View answer and explanationThe symbol 'x̄' represents what concept in Chapter 7?
View answer and explanationIf a sample size is considered 'large enough', what does the Central Limit Theorem allow us to do?
View answer and explanationWhy is the Central Limit Theorem considered one of the most powerful and useful ideas in all of statistics?
View answer and explanationWhat is the standard deviation of the sampling distribution of proportions if the population proportion is 0.1 and the sample size is 50?
View answer and explanationIn Figure 7.2 on page 316, the top panel shows a 'squiggly' unknown population distribution. What does the bottom panel, representing the sampling distribution of means, look like?
View answer and explanationA college gives a placement test to 5,000 students. On average, 1,213 place into developmental courses. This represents a proportion of 0.2426. If a sample of 50 is taken, what is the probability at most 12 of them will be in developmental courses?
View answer and explanation