Homework answers / question archive / Liberty Christian Academy, Lynchburg - BMAL ALC 9 Week 5 Section 1)What is Statistics?                       Questions: You take a random sample of 100 students at your university and find that their average GPA is 3

Liberty Christian Academy, Lynchburg - BMAL ALC 9 Week 5 Section 1)What is Statistics?                       Questions: You take a random sample of 100 students at your university and find that their average GPA is 3

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Liberty Christian Academy, Lynchburg - BMAL

ALC 9 Week 5

Section 1)What is Statistics?

 

 

 

 

 

            Questions:

1. You take a random sample of 100 students at your university and find that their average GPA is 3.1. If you use this information to help you estimate the average GPA for all students at your university, then you are doing what branch of statistics?
2. A company has developed a new computer sound card who average lifetime is unknown. In order to estimate this average, 200 sound cards are randomly selected from a large production line and tested; their average lifetime is found to be 5 years. The 200 sound cards represent a:
3. A company has developed a new computer sounds card who average lifetime is unknown. In order to estimate this average, 200 sound cards are randomly selected from a large production line and tested; their average lifetime is found to be 5 years. The five years represents a:
4. A summary measure that is computed from a population is called a:
5. Which of the following is a measure of the reliability of a statistical inference?
6. The process of using sample statistics to draw conclusions about population parameters is called:
7. Which of the following represents a population, as opposed to a sample?
8. A study in under way to determine the average height of all 32,000 adult pine trees in a certain national forest. The heights of 500 randomly selected adult pine trees are measured and analyzed. The sample in this study is:
9. The significance level of a statistical inference measures:
10.  The confidence level of a statistical inference measures:

 

Section 2- Data Collection and Sampling

 

            Questions:

1. A marketing research firm selects a random sample of adults and asks them a list of questions regarding their beverage preferences. What type of data collection is involved here?
2. Which of the following statements is true regarding the design of a good survey?
3. Which method of data collection is involved when a researcher counts and records and number of students wearing backpacks on campus on a given day?
4. The difference between a sample mean and the population mean is called:
5. The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a videocassette recorder over the past 12 months are satisfied with their products.
6. When every possible sample with the same number of observation is equally likely to be chosen, the result is called a:
7. Which of the following types of samples is almost always biased?
8. Which of the following is an example of a nonsampling error?
9. Which of the following situations lends itself to cluster samples?
10.  Which of the following causes sampling error?
11.  Which of the following describes selection bias?

 

Section 3- Probability

 

            Question:

1. An approach of assigning probabilities which assumes that all outcomes of the experiment are equally likely is referred to as the:
2. The collection of all possible outcomes of an experiment is called:
3. If event A and event B cannot occur at the same time, then A and B are said to be:
4. Which of the following best describes the concept of marginal probability?
5. The intersection of events A and B is the event that occurs when:
6. If the outcome of event A is not affected by event B, then events A and B are said to be:
7. Suppose P(A) = 0.35. The probability of the complement of A is:
8. If the event A and B are independent with P(A)= 0.30 and P(B) = 0.40, then the probability that both events will occur simultaneously is:
9. If A and B are mutually exclusive events with P(A) = 0.30 and P(B)= 0.40, then P(A or B) is:
10.  Bayes’ Law is used to compute:
11.  Initial estimates of the probabilities of events are known as:

 

Section 4- Sampling Distribution

 

            Questions:

1. The standard deviation of the sampling distribution of x is also called the:
2. The central Limit Theorem states that, if a random sample of size n is drawn from a population, then the sampling distribution of the sample mean:
3. If all possible samples of size n are drawn form a population, the probability distribution of the sample mean x is called:
4. Sampling distribution describe the distribution of:
5. Suppose X has a distribution that is not normal. The Central Limit Theorem is important in this case because:

 

6. As a general rule, the normal distribution is used to approximate the sampling distribution of the sample proportion only if:
7. The standard deviation of p is also called the:
8. If two population are normally distributed, the sampling distribution of the difference in the sample means x1- x2 is:
9. If two random samples of sizes n1 and n2 are selected independently from two populations with means u1 and u2, then the mean of x1 – x2 equals.
10.  If two random samples of size n1 and n2 are selected independently from two non-normally distribution populations, then the sampling distribution of the sample mean difference, x1 – x2.
11.  The standard deviation of x1 – x2 is also called the:

 

Section 5- Introduction To Hypothesis Testing

 

            Questions:

1. The hypothesis of most interest to the researcher is:
2. A Type I error occurs when we:
3. A type II error is defined as:
4. Which of the following probabilities is equal to the significance level a?
5. If we reject the null hypothesis, we conclude that:
6. Statisticians can translate p-values into several descriptive term. Suppose you typically reject H0 at level 0.05. Which of the following statements is correct?
7. The p-value of a test is the:
8. The numerical quantity computed from the data that is used in deciding whether to reject H0 is the:
9. For a given level of significance, if the sample size increases, the probability of a Type II error will:
10.  The power of a test is measured by its capability of:
11.  If the probability of committing a Type I error for a given test is decreased, then for a fixed sample size n, the probability of committing a Type II error will:

 

Section 6- Inference About A Population

           

            Questions:

1. A robust estimator is one that is:
2. For statistical inference about the mean of a single population when the population standard deviation is unknown
3. The degree of freedom for the test statistic of u when o is unknown is:
4. The statistic (n-1) s2 / o2 has a chisquared distribution with n-1 degrees of freedom if:
5. Which of the following is an example illustrating the use of variance?
6. Which of the following conditions is needed regarding the chi-squared test statistic for the test of variance?
7. Under what condition does the test statistic for p have an approximate normal distribution?
8. In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the approximate values of the sample proportion p, we:
9. When determining the sample size needed for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be:
10.  Which of the following would be an appropriate null hypothesis?

 

 

 

 

Section 7- Analysis of Variance

           

            Questions:

1. The analysis of variance is a procedure that allows statisticians to compare two or more population.
2. The distribution of the test statistic for analysis a variance is the:
3. In one-way analysis of variance, between-treatments variation is measured by the:
4. When is the Tukey multiple comparison method used?
5. In Fisher’s least significant difference LSD multiple comparison method, the LSD value will be the same for all pairs of means if:
6. Fisher’s least significant difference LSD multiple comparison method is flawed because:
7. When the objective is to compare more than two populations, the experimental design that is the counterpart of the matched pairs experiment is called a:
8. The primary interest of designing a randomized block experiment is to:
9. A complete 3 x 2 factorial experiment is called balanced if:
10.  In a two-factor ANOVA, there are 4 levels for factor A, 5 levels for factor B, and 3 observations for each combination of factor A and factor B levels. The number of treatments in this experiment equals.

 

Section 8- Decision Analysis

 

            Questions:

1. A tabular presentation that shows that outcome of each decision alternative under the various states of nature is called a:
2. Which of the following would be considered a state of nature for a business firm?

 

3. A payoff table lists the monetary values for each possible combination of the:
4. Which of the following is true?
5. Which of the following statements is false regarding the expected monetary value (EMV)?
6. Which of the following statements is correct?
7. The expected value of perfect information is the same as the:       
8. The expected value of sample information (EVSI) is the difference between
9. The procedure for revising probabilities based upon additional information is referred to as:
10.  The difference between expected payoff under certainty and expected value of the best act without certainty is the;