Quantitative Research Techniques and Statistics - Peregrine Exam, Exams of Nursing

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QUANTITATIVE RESEARCH TECHNIQUES + STATISTICS – PEREGRINE EXAM QUANTITATIVE RESEARCH TECHNIQUES + STATISTICS – PEREGRINE EXAM |GUARANTEED PASS A company developed a smartphone whose average lifetime is unknown. In order to estimate the average, 200 smartphones are randomly selected from a large production line and tested; their average is found to be 5 years. The 200 smartphones represent: - ACCURATE ANSWERS✔✔ a sample Significance level - ACCURATE ANSWERS✔✔ Measures the reliability of a statistical inference inferential statistics - ACCURATE ANSWERS✔✔ Process of using sample statistics (mathematics) to draw conclusions about population parameters mutually exclusive - ACCURATE ANSWERS✔✔ Events that cannot occur at the same time.

sampling error - ACCURATE ANSWERS✔✔ the difference between the results of random samples taken at the same time non-sampling error - ACCURATE ANSWERS✔✔ occurs when the sample data are incorrectly collected, recorded, or analyzed. Three types of errors: data acquisition errors, non-response errors (or bias), selection bias Design of a good survey components - ACCURATE ANSWERS✔✔ short survey, short/simple questions, start with demographic questions, ues dichtomous (yes-no) and multiple choice Direct observation - ACCURATE ANSWERS✔✔ example: counts backpacks on campus for a day stratified random sample - ACCURATE ANSWERS✔✔ a sample from selected subgroups of the target population in which everyone in those subgroups has an equal chance of being included in the research example: The manager of a customer service division wants to know if the customers in the past 12 months are satisfied with their purchase of CD's. There are four types of CD's. Joint Probability - ACCURATE ANSWERS✔✔ the probability of the intersection of two events

Union of two events - ACCURATE ANSWERS✔✔ The union of events A and B is the event containing all sample points that are in A or B or both Marginal Probability - ACCURATE ANSWERS✔✔ the probability of a single event without consideration of any other event Conditional Probability - ACCURATE ANSWERS✔✔ the likelihood that a target behavior will occur in a given circumstance Bayes Law - ACCURATE ANSWERS✔✔ calculates posterior probability exhaustive - ACCURATE ANSWERS✔✔ including everything possible; very thorough or complete Central Limit Theorem (CLT) - ACCURATE ANSWERS✔✔ The name of the theorem stating that the sampling distribution of a statistic (e.g. x ) is approximately normal whenever the sample is large and random. Allows us to draw conclusions about the population based on strictly sample data. sampling distribution of the mean - ACCURATE ANSWERS✔✔ 1. the sampling distribution of the mean has a different mean from the original population

2. the standard deviation of the sampling distribution of the mean is referred to as the standard deviation
3. if the original population is not normally distributed, the sampling of the mean will be normal Suppose you are given 3 numbers that relate to the number of people in a sample. The three numbers are 10, 20 and 30. If the standard deviation is 10, the standard error equals - ACCURATE ANSWERS✔✔ 5. To find the standard deviation, find the mean of the data set ( 10, 20, 30) then calculate in excel. Watch video Bozeman Science Standard Error Find the sample standard deviation of 5, 10, 15 and 20. - ACCURATE ANSWERS✔✔ 6. standard deviation - ACCURATE ANSWERS✔✔ a computed measure of how much scores vary around the mean score Type 1 error - ACCURATE ANSWERS✔✔ Rejecting null hypothesis when it is true type 11 error - ACCURATE ANSWERS✔✔ false negative Type 1 error criminal - ACCURATE ANSWERS✔✔ Innocent person is wrongly convicted

The hypothesis of most interest to the researcher is: - ACCURATE ANSWERS✔✔ the alternative hypothesis p-value - ACCURATE ANSWERS✔✔ The probability level which forms basis for deciding if results are statistically significant (not due to chance). Variance - ACCURATE ANSWERS✔✔ the square of the standard deviation one-tailed test - ACCURATE ANSWERS✔✔ A hypothesis test in which rejection of the null hypothesis occurs for values of the test statistic in one tail of its sampling distribution. unbiased estimator - ACCURATE ANSWERS✔✔ a sample statistic which has an expected value equal to the value of the population parameter Suppose a population of blue whales is 8000. Researchers are able to garnish a sample of oceanic movements from 100 blue whales within the population. Thus,

• researchers do not have a significant sample size
• researchers need a larger population of blue whales
• the finite population correction factor is necessary

• researchers can ignore the finite population correction factor - ACCURATE ANSWERS✔✔ researchers can ignore the finite population correction factor In a sample proportion, represented by p = x/n, what does X refer to? - ACCURATE ANSWERS✔✔ # of successes in the sample The branches in a decision tree are equivalent to - ACCURATE ANSWERS✔✔ events and acts What is needed to compute posterior probabilities? - ACCURATE ANSWERS✔✔ The sum of all the P(sj and li)'s, likelihood probabilities, p (li/sj) doing inferential statistics. - ACCURATE ANSWERS✔✔ The process of using sample statistics to draw conclusions about population parameters is called The confidence level - ACCURATE ANSWERS✔✔ measures the proportion of times an estimation procedure will be correct in the long run Parameter - ACCURATE ANSWERS✔✔ a summary measure that is computed

sample space - ACCURATE ANSWERS✔✔ the set of all possible outcomes of a probability experiment prior probabilities - ACCURATE ANSWERS✔✔ initial estimates of the probabilities of events the standard error of the sample mean - ACCURATE ANSWERS✔✔ standard deviation of the distribution of the sample means , Standard deviation/sq rt (population size) Business Statistics - ACCURATE ANSWERS✔✔ the collection, summarization, analysis, and reporting of numerical findings relevant to a business decision or situation descriptive statistics - ACCURATE ANSWERS✔✔ uses graphical or numerical techniques to summarize and present data mean - ACCURATE ANSWERS✔✔ average measure of variability - ACCURATE ANSWERS✔✔ how closely scores bunch up around the central point; a statistic that indicates the spread of distribution range - ACCURATE ANSWERS✔✔ the difference between the highest and lowest scores in a distribution

Median - ACCURATE ANSWERS✔✔ the middle score in a distribution; half the scores are above it and half are below it Mode - ACCURATE ANSWERS✔✔ the most frequently occurring score(s) in a distribution Variance - ACCURATE ANSWERS✔✔ the average of the squared deviations from the mean standard deviation - ACCURATE ANSWERS✔✔ the square root of the variance and provides a measure of the standard, or average, distance from the mean Three concepts that a statistical inference problem contains - ACCURATE ANSWERS✔✔ the population, the sample, and the statistical inference Parameter - ACCURATE ANSWERS✔✔ a descriptive measure of a population statistic - ACCURATE ANSWERS✔✔ a number that describes a sample statistical inference - ACCURATE ANSWERS✔✔ process of making an estimate, prediction, or decision about a population based on a sample

confidence level - ACCURATE ANSWERS✔✔ Proportion of times that an estimating procedure will be correct Confidence level + significance level - ACCURATE ANSWERS✔✔ = 1 simple random sampling - ACCURATE ANSWERS✔✔ A sampling procedure in which each member of the population has an equal probability of being included in the sample. (example - tickets in a bin each assigned a number) stratified random sampling - ACCURATE ANSWERS✔✔ obtained by separating the population into mutually exclusive sets of data (strata) then drawing a simple random sample from each stratum cluster sampling - ACCURATE ANSWERS✔✔ random sample of the groups or clusters of elements versus a simple random sample of individual objects Probability of any outcome must be between - ACCURATE ANSWERS✔✔ 0 and 1 Sum of all probabilities must equal: ____ - ACCURATE ANSWERS✔✔ 1

Three approaches to assigning probability - ACCURATE ANSWERS✔✔ classical approach, relative frequency approach, subjective approach Classical Approach to Probability - ACCURATE ANSWERS✔✔ associated with games of chance. If an experiment has N possible outcomes, this method would assign probability of 1/n to each customer. For example, the probability of a heads and tails in the flip of a coin are equal to each other. Because the sum must be 1, the probability is 1/2, or 1/6 for a dice. relative frequency approach to probability - ACCURATE ANSWERS✔✔ defines probability as the long run frequency in which something occurs. Example: the last 1000 students took a course, 200 got an A. The relative frequency is 20% - estimate of students that will get an A subjective approach to probability - ACCURATE ANSWERS✔✔ the probability is obtained on the basis of personal judgement; often the only method of assigning likelihood to an outcome; educated guess based on knowledge available union of two events - ACCURATE ANSWERS✔✔ Given by the outcomes that belong either to one or to both events. calculate conditional Probability - ACCURATE ANSWERS✔✔ P (A1/B2)

Complement Probability - ACCURATE ANSWERS✔✔ event that occurs when A does not occur. P(A) + P(Ac) = 1 multiplication rule - ACCURATE ANSWERS✔✔ To determine the probability, we multiply the probability of one event by the probability of another. Addition Rule of Probability - ACCURATE ANSWERS✔✔ P(A or B) = P(A) + P(B) - P(AB) standard error - ACCURATE ANSWERS✔✔ the standard deviation of a sampling distribution Complement of an event - ACCURATE ANSWERS✔✔