STATS Final Exam
Mean academic performance will decrease
A researcher believes that increasing attention to give children will improve mean academic performance. Therefore the alternative hypothesis should be:
Reject the null hypothesis; IQ scores in the sample are significantly higher than those in the population.
A researcher selects a sample of 36 students from the school population with a mean IQ of 100 and a standard deviation of 12. She found that the mean IQ in the sample is 104. Assuming she conducts a one sample Z test at a 0.05 level of significance what is the decision for a two tailed test?
Nominal
Ab education counselor records the number of high school graduates enrolled in community colleges, four year colleges, and universities. What scale of measurement is the type of college?
Effective size
Allows researchers to describe how far mean scores have shifted in the population or the percentage of variance that can be explained by given variable.
Decreases
As sample size increases, the standard error of the mean
Small effect size
Based on the effect size conventions, D= 0.18 is a
Have equidistant scales
Interval scales of measurement
The criteria for a decision regarding the value stated in a null hypothesis is that by the
Level of significance and p value
approximate
Most behavior is believed to blank a normal distribution
Inferential statistics
Procedures that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected best describes
qualitative; quantitative
Recording whom students study with describes blank types of data, where as recording the number of hours spent studying per week describes blank types of data
This advanced training seminar did not reduce response time, t(35)= -1.43, p is greater than 0.05
The average response time to a bank robbery is about nine minutes. A local community wants to improve on this time, so they implement advanced training seminars. They find that the new response time for a sample of 36 police officers is 8 to 4.2 minutes test whether this advanced training seminar reduced response time at a .05 level of significance.
If the value of the test statistic is in the rejection region, then
The decision is to reject the null hypothesis, the value of the test statistic is larger than the critical value, and P is less than .05
The degrees of freedom
Using APA format, which value is typically given in parentheses when reporting the results for a T test?
1.96
What is the Z score for score is in the top 2.5%?
12
What is the value of SS for the following population? Population: one, one, one, five
Experimental
A researcher test whether the dosage level of some drug flow, high causes significant differences in health. To do this, the researcher randomly assigns rat subjects to receive a lower high dose of the drug and records of health related measures in both groups. The type of method described is
Sample statistic
A characteristic usually numeric that describes a sample is called
0.8413
A counselor records the number of disagreements per session among couples during group counseling sessions. if the number of disagreements is distributed normally as 4.4-.4 For disagreements then what proportion of couples disagree at least four times during each counseling session?
Histogram
A graphical display for group frequency distributions with continuous data is called
When can the score not be determined in a distribution?
A group frequency loses individual X values
Variance
A measure of the average square distance of scores from the mean is called the
Hypothesis testing
A method for testing a claim or hypothesis about a parameter in a population, using data measured in a sample is called
d= 0.62 (medium effect)
A professor commutes the main difference in exam scores before and after lecture as 9 to 14.5. And this difference was significant. What is the effect size for this result using estimatedof Cohen's d?
u=78
A professor gives an exam in which means score is 78 points. She gives another exam to test whether or not the scores change in this example the null hypothesis is
85.56
A professor records the following exam scores: 78 to 7. Student scoring in the top 14% get a name. What is the cut off score for the top 14% in this example?
7.1 sessions
A psychologist treat 16 patients and records the number of sessions required to complete a behavioral therapy treatment for each patient. She computers SS equals 800. Assuming the 16 patients constitute all patients under her care what is the standard deviation for these data?
0.0228
A researcher Celexa sample of 25 participants from a population with a mean of 10 and a standard deviation of five. What is the probability of selecting a sample mean that is at least two standard deviation's larger than the population mean?
Mode
A researcher asks adult participants to rank their top five favorite songs from their childhood based on the scale of measurement described, which measure of central tendency is most appropriate to describe these data?
Risk levels in the population shifted 0.64 standard deviation's below the mean
A researcher conducts a study and concludes that a new behavioral health treatment program significantly reduces one's risk for disease compared with risk levels in the general population D equals -0.64. Interpret the size of this effect
The amount of St. John's wort given to each participant
A researcher conducts an experiment to determine whether moderate doses of St. John's wort have any effect on memory for college students. For this study what is the independent variable?
-1
A researcher determines that the students study an average of 80 to 20 minutes per week assuming these data or normally distributed what is the Z score for student studying 60 minutes per week?
No, this result is not significant, t(30)=0
A researcher has participants rate the likability of sexual promiscuous person described in vignette as being male, n=equals 20 or female, n=12. The mean likability ratings in each group were 4.0. If the null hypothesis is that there is no difference in likability ratings, then do likability ratings differ at a .05 level of significance?
The small group of college students who here observed
A researcher identifies college students as a group of interest to test your hypothesis. She then identifies a few local college students and selects a small group of local college students to be observed in this example the sample is:
+-2.045
A researcher matched 30 participants on intelligence 15 pairs of participants, and then compare differences in emotional responsiveness to two experimental stimuli between each pair. For this test what are the critical values, assuming a two tailed test at a .05 level of significance?
interval
A researcher measures the body temperature in degrees Fahrenheit of participants immediately before and immediately following sleep. Temperature is on what scale of measurement?
Sample A
A researcher measures the number of trials it takes two samples of participants to master a new task. In both samples, SS equals 240. Sample a consisted of 12 participants and sample b consisted of 18 participants. Which sample is associated with the largest variance?
To retain the null hypothesis
A researcher obtains Z equals -6.45. What is the decision for a one tailed test, upper tail critical, at a .05 level of significance?
Mean= 12, standard error= 0.5
A researcher randomly selects a sample of participants from a population with a variance of four. If a researcher selects a sample of 16 participants with a mean of 12, then what is the mean and standard error for the sampling distribution of this mean?
47.04
A researcher records the following assessment data 42 to 6. The researcher only wants to sample participants scoring in the top 20% of this assessment. What is the cut off score for the top 20% in this example?
Yes
A researcher records the following data for the number of dreams are called during a night of sleep for 10 college students three, two, four, four, three, one, one, zero, two, and zero. Is the mean equal to the median in this example?
19.68 minutes
A researcher records the following times in seconds that it took for a group of students to complete an exam 18 to 2 minutes. How long did it take 80% of students to complete the exam?
One sample t test
A researcher records the number of distractors such as noises that preschool age children ignore while watching a popular Sunday morning cartoon show. Assuming that the population variance is unknown, what type of t-test is appropriate for the study?
Descriptive statistics
A researcher records the number of votes for each five candidates running for class president. Based on her presentation of the following results, what type of statistic that she use? A-120 B-125 C-42 D-203 E-20
95% of the class were between 68 and 92 dB
A researcher records the sound during a series of lessons taught by a substitute teacher at a local elementary school. In his study he found that the sound was 80 to 6 dB assuming the data are normally distributed which of the following is an appropriate conclusion?
d=0.53; medium effect size
A researcher reports that the main difference in response time to an auditory versus a visual cue is 0.83 seconds, with a pool sample variance equal to 2.45. What is the effect size for this test using estimated Cohen's d?
A related samples t-test is the correct test for the study; the result of the test is significant
A researcher selected a sample of 24 participants and observe their behavior at two times. The result of related samples t test at a .05 level of significance was t=2.68. Which of the following correctly describes the result of this test?
Equal to the probability of selecting a sample mean that is smaller than eight
A researcher selects a sample of 25 participants from a population with a mean of 10 and a standard deviation of five what is the probability of selecting a sample mean equal to at least 12?
None both samples will have the same value for standard error
A researcher selects two samples of 25 participants each. The first sample is from the population where the population mean was 32 and the variance was eight. The second sample from the population were the population mean was four and the variance was eight. Which sample will be associated with a larger standard error of the mean?
40
A researcher states that a sample of 100 shoppers spend $112-$40 on groceries each week. Which value is the standard error of the mean?
Retain the null hypothesis; responses were not more accurate under hypnosis
A researcher test how well participants know their spouse well under hypnosis, and again without hypnosis. It was hypothesize that participant responses would be more accurate greater number of correct responses when under hypnosis. The main number of correct responses was M equals 5.3 under hypnosis and M equals 3.4 without hypnosis in a sample of 30 participants. If the estimated standard error for different scores was 2.52, then what is the decision at a .05 level of significance two tailed test?
The student scored higher than 80% of all others who took the exam
A student scores in the 80th percentile on an exam. What does this mean in comparison to all the other students?
Repeated measures design
A type of related samples design in which participants are observed more than once is called
Nominal
An animal researcher measures the number of times a rat presses a lever located at the right, center, and left of a cage for a food reward. What scale of measurement is the location of the lever pressing?
A simple frequency distribution
Can we use to summarize group data, summarized ungroup data, and summarizes the frequency of scores in a given category or range
8
Elementary school children spent significantly more time reading the presence of a teacher then when the teacher was absent,t(7)= 2.804, p is less than .05. In this related samples t-test how many participants were observed?
In a normal distribution, 50% of all data
Fall above the mean, below the median, and fall above or below the mode
A equals 3.2, B equals 13
Fill in the missing values for A and B in this frequency distribution table
To retain the null hypothesis
Given the following values: u=6;x bar=7.6; n=36; o=6, conduct a one sample Z test at a .05 level of significance. For a one tailed test, upper tail critical, what is the decision?
independent variable
Is the variable in an experiment that is manipulated between conditions being observed
A researcher distributes frequencies into the following classes absent, tardy, present. What type of data are distributed?
Nominal data, qualitative data, ungroup data
Computing a one sample t-test is appropriate when
Participants are assigned to only one group, the population variance is unknown, and participants are observed one time
Sample;population
Researchers measure data in a blank to learn more about individuals in a larger blank of interest
They record data from a sample of people in the larger population in order to make inferences concerning characteristics in that larger population.
Researchers rarely have access to entire populations how do you researchers resolve this limitation?
+-2.086
State the critical values for a T test using a two tailed test at a .05 level of significance: t(20).
The class intervals overlap
State the problem with this simple frequency distribution. Intervals: 8-10 6-8 4-6 2-4 0-2
The new naptime routine significantly reduced crying time, t(24)=-4.35, p is less than 0.05
The main crying time of infants during naptime at a local preschool is 12 minutes. The school implements a new naptime routine and a sample of 25 infants and requires an average crying time of 8 to 4.6 minutes. Test whether this new naptime routine reduce crying time at a .05 level of significance.
Coding
The procedure of converting a categorical variable to numeric values is called:
To reject the null hypothesis for an upper tailed test, but to retain the null hypothesis for a two tailed test
The professor finds that the average SAT score among all students attending his college is 1150 to 150. He pulls his class of 25 students and find out the average SAT score is 1200. Suppose he computes a one samples he test at 8.05 level of significance. What is his decision?
df; N
The sample variance is computed by dividing SS by blank; where areas the population variance is computed by dividing SS by blank
Difference scores
The test statistic for a related samples t-test makes tests concerning a single sample of
z-score
The unit of measurement distributed along the horizontal axis of a standard normal distribution is referred to as a
Descriptive statistics
The use of tables and graphs to summarize data is an example of
Randomization, manipulation, and comparison/control
Three key elements of control that allow researchers to draw a cause and effect conclusions are
Experimental, quasiexperimental, and correlational
Three research methods common to research in the behavioral sciences are
Real range
To determine the interval with, we divide the blank by the number of intervals
0.05
What type of level of significance for a hypothesis test in behavioral research?
The measured behavior
Which of the following is best described as a dependent variable
The proportion of area between z= +1 and -1
Which proportion is largest in a Z distribution?
A researcher records the following data for how participants rated the likability of an individual who blushed after making a mistake five, four, seven, six, six, four, six, seven, two, five, and six. Is the most equal to the median in this example?
Yes
