Scientific Method And Research Study, Variance – Midterm Statistics
The key terms in these Statistic chapters include Variance, Scientific Method, Distribution, Hypothesis, Research Study, Distribution Table, Population, Weighted Average, Normal Distribution – Statistic
What the variance for the following sample of n = 3 scores? Scores: 1, 4, 7
9
For the scores in the following table, what is the value of ΣX 2? (X: 3,2,1 f: 1, 2, 4)
21
A set of scores ranges from a high of X = 45 to a low of X = 11. If these scores were placed in an appropriately designed grouped frequency distribution table, which of the following would be the bottom interval in the table?
10-14
Which statement below must be false regarding a distribution of scores?
75% of the scores are above the median
Which statement below is consistent with computing a weighted average of two individual samples?
A computed weighted average will always be closer to the mean average of the larger sample than the mean average of the smaller sample.
Jean Piaget observed his own children and developed a theory about the cognitive development of all children. What kind of reasoning was that?
Inductive
In the scientific method, the actual research study is not done until after the researcher has formed a hypothesis and made a specific prediction.
True
Quantitative research and qualitative research: what’s the difference?
They generate different types of data
Using observations of a small number of humans to Making a general statement about human behavior based on observations of a few people. What kind of reasoning is that?
Inductive
A population is normally distributed with µ = 86 and σ = 12. For this population, what is the 78 th percentile?
X = 95.24
Delores must grade a driver’s test completed by a group of training students. She knows that driver’s test scores are normally distributed with µ = 50 and σ = 6. Students are required to score in the top 75% of students on the test in order to pass the test and continue on with the training course. Which score do students need to obtain at a minimum in order to pass the test and continue with the course?
X = 46
What is the probability of randomly selecting a z-score less than z = -1.55 from a normal distribution?
p = 0.0606
A normal distribution has a mean of µ = 50 with σ = 6. If one score is randomly selected from this distribution, which is the probability that the score will be greater than X = 46?
p = 0.7486
A researcher is interested in whether a new reading technique influences the reading ability of elementary school children. The researcher knows that average reading ability among a population of third graders is µ = 3 with a standard deviation of σ = 1. If the researcher administers the new reading technique to a third grader who subsequently scores X = 4, it can be concluded that the new reading technique _____.
Does not have an influence on reading ability.
What the variance for the following sample of n = 3 scores? Scores: 1, 4, 7
9
For the scores in the following table, what is the value of ΣX 2? (X: 3,2,1 f: 1, 2, 4)
21
A set of scores ranges from a high of X = 45 to a low of X = 11. If these scores were placed in an appropriately designed grouped frequency distribution table, which of the following would be the bottom interval in the table?
10-14
Which statement below must be false regarding a distribution of scores?
75% of the scores are above the median
Which statement below is consistent with computing a weighted average of two individual samples?
A computed weighted average will always be closer to the mean average of the larger sample than the mean average of the smaller sample.
Jean Piaget observed his own children and developed a theory about the cognitive development of all children. What kind of reasoning was that?
Inductive
In the scientific method, the actual research study is not done until after the researcher has formed a hypothesis and made a specific prediction.
True
The distribution of z-scores corresponding with a population of scores always has a variance of _____.
σ^2 = 1.
A person scores X = 65 on an exam. Which set of parameters would give this person the worst grade on the exam relative to others?
µ = 70 and σ = 5
Which z-score corresponds to a score that is above the mean by 2 standard deviations?
+2
Which of the following statements must be false regarding a distribution of scores?
No individual has a score exactly equal to the mode.
One sample with n = 4 scores has a mean of M = 12, and a second sample with n = 6 scores has a mean of M = 8. If the two samples are combined, what is the mean for the combined set of scores?
M = 9.6
Which of the following symbols identifies the population standard deviation?
σ
Which symbol below identifies the sample variance?
s^2
Compute the interquartile range for the following scores that represent a continuous variable: 1, 2, 2, 2 4, 5, 10, 12
3
A frequency distribution graph represents frequencies associated with scores for a variable with vertical bars that have space between them. Which scale of measurement was used to measure this variable?
Nominal
A researcher surveys a sample of n = 20 college students and asks each person to identify their favorite movie. If the data were organized in a frequency distribution table, what would be included in the last column?
List of frequencies
A good hypothesis should make a positive statement about the existence of a relationship, a difference, or a treatment effect.
True
Which section of a research article can help you to develop ideas for studies by changing the characteristics of the participants or modifying the procedures for your own study?
Method
A birdwatcher puts several types of seed in her backyard to see which type attracts the most birds. Which method of acquiring knowledge is she using?
Method of empiricism
Observation, followed by hypothesis, followed by more observation. What’s going on?
Scientific method
Which proportion of a normal distribution is located between z = -1.75 and z = +1.75?
0.9198
A class consists of 10 male students and 30 female students. If one student is randomly selected from the class, what is the probability of selecting a male student?
p = 10/40
Which proportion of a normal distribution is located in the tail above z = +1.50?
0.0668
Which statement accurately describes the proportions in the body of a normal distribution?
Body proportions are always ≥ .50.
Which of the following symbols identifies the population standard deviation?
σ
Which symbol below identifies the sample variance?
s^2
Compute the interquartile range for the following scores that represent a continuous variable: 1, 2, 2, 2 4, 5, 10, 12
3
A researcher is interested in examining whether self-affirming oneself leads to decreased anxiety in response to threatening information. The researcher conducts a research study in which an individual is self-affirmed prior to receiving threatening information. Researchers know that on average individuals tend to have anxiety levels of µ = 10 with a standard deviation of σ = 2 when presented with this threatening information. If a self-affirmed individual has an anxiety level of X = 5 following the threatening message, it is reasonable to conclude that self-affirmation ______.
Does have an influence on anxiety levels following threatening information.
What the variance for the following sample of n = 3 scores? Scores: 1, 4, 7
9
For the scores in the following table, what is the value of ΣX 2? (X: 3,2,1 f: 1, 2, 4)
21
A set of scores ranges from a high of X = 45 to a low of X = 11. If these scores were placed in an appropriately designed grouped frequency distribution table, which of the following would be the bottom interval in the table?
10-14
Which statement below must be false regarding a distribution of scores?
75% of the scores are above the median
Which statement below is consistent with computing a weighted average of two individual samples?
A computed weighted average will always be closer to the mean average of the larger sample than the mean average of the smaller sample.
Jean Piaget observed his own children and developed a theory about the cognitive development of all children. What kind of reasoning was that?
Inductive
In the scientific method, the actual research study is not done until after the researcher has formed a hypothesis and made a specific prediction.
True
One sample with n = 4 scores has a mean of M = 12, and a second sample with n = 6 scores has a mean of M = 8. If the two samples are combined, what is the mean for the combined set of scores?
M = 9.6
A frequency distribution graph represents frequencies associated with scores for a variable with vertical bars that have space between them. Which scale of measurement was used to measure this variable?
Nominal
A researcher surveys a sample of n = 20 college students and asks each person to identify their favorite movie. If the data were organized in a frequency distribution table, what would be included in the last column?
List of frequencies
A good hypothesis should make a positive statement about the existence of a relationship, a difference, or a treatment effect.
True
Which section of a research article can help you to develop ideas for studies by changing the characteristics of the participants or modifying the procedures for your own study?
Method
A birdwatcher puts several types of seed in her backyard to see which type attracts the most birds. Which method of acquiring knowledge is she using?
Method of empiricism
Observation, followed by hypothesis, followed by more observation. What’s going on?
Scientific method
A person scores X = 65 on an exam. Which set of parameters would give this person the worst grade on the exam relative to others?
µ = 70 and σ = 5
The distribution of z-scores corresponding with a population of scores always has a variance of _____.
σ^2 = 1.
Using observations of a small number of humans to Making a general statement about human behavior based on observations of a few people. What kind of reasoning is that?
Inductive
What is the probability of randomly selecting a z-score less than z = -1.55 from a normal distribution?
p = 0.0606
Quantitative research and qualitative research: what’s the difference?
They generate different types of data
A good hypothesis should make a positive statement about the existence of a relationship, a difference, or a treatment effect.
True
Which section of a research article can help you to develop ideas for studies by changing the characteristics of the participants or modifying the procedures for your own study?
Method
A birdwatcher puts several types of seed in her backyard to see which type attracts the most birds. Which method of acquiring knowledge is she using?
Method of empiricism
A birdwatcher puts several types of seed in her backyard to see which type attracts the most birds. Which method of acquiring knowledge is she using?
Method of empiricism
Observation, followed by hypothesis, followed by more observation. What’s going on?
Scientific method
A person scores X = 65 on an exam. Which set of parameters would give this person the worst grade on the exam relative to others?
µ = 70 and σ = 5
The distribution of z-scores corresponding with a population of scores always has a variance of _____.
σ^2 = 1.
Which of the following symbols identifies the population standard deviation?
σ
Which symbol below identifies the sample variance?
s^2
Compute the interquartile range for the following scores that represent a continuous variable: 1, 2, 2, 2 4, 5, 10, 12
3