PSYC 2901: Final Exam (Cumulative)

A researcher predicts treatment will increase scores, using a directional hypothesis where is the critical region?

Are we ready

If a distribution is symmetrical its considered normal.

In a distribution of exam scores, which of the following would be the highest score?

What is the cumulative percentage for the interval 52-55?

n = 15 pairs of scores (X and Y values) has SSX = 4, SSY = 25, and SP = 6. What is the Pearson correlation?

If a histogram shows bars that tend to decrease in height from left to right, then...

In a sample size of 10, ΣX = 30, ΣY = 20, and ΣXY = 74. Calculate SP.

A histogram is discrete

treatment to sample selected from a pop mean of µ = 80 and a sd of σ = 10. After treatment M = 85. Calculate cohen's d:

When a score is identified by its percentile rank, the score is called a...

What is the standard deviation for the following sample of scores? 1, 5, 6, 9, 7, 3

For the following frequency distribution, how many individuals had a score of X = 2?

Of the following z-score values, which represents the most extreme location on the left-hand side of the distribution?

What does a Pearson’s r of -0.70 tell us?

What is the range of possible values for Pearson's r?

When does a researcher risk a Type I error?

The sum of the squared deviation scores is SS = 60 for a n = 10 scores Whats the standard deviation for this sample?

In a normal distribution, why is the sum of deviations from the mean always equal to zero?

Why would we transform our z-score data into t-scores with a predetermined mean and standard deviation

A pre-determined mean μ 500 and SD σ of 100 Z = +1.50 what was the raw score if original μ 50 σ 10?

N = 100 Baron has 95 sootcases that have a mini one inside calculate the probability that hes using one w/o a mini

What's an example of a ratio scale measurement?

A cohens d of '0.4' represents what kind of effect

When is a classical probability used?

The mode is the middle value in the dataset. Central point of data, robust/insensitive to extreme values.

What does a z-score of -1.00 indicate?

t-distribution shape is defined by the degrees of freedom related to the sample size.

A cohens d can be negative

For a sample with M = 60 and s = 8, what is the z-score corresponding to X = 62?

Whats the following mean for the sample of scores: 2,4,5,9 

What happens to the shape of the t-distribution as sample size increases?

What proportion of a normal distribution is located in the tail above z = +1.50?

Out of N = 5900; 354 abused alcohol, 236 abused drugs (118 used both, same group) Calculate how many used either or:

What does homoscedasticity assume?

The median is the middle value in the dataset. Central point of data, robust/insensitive to extreme values.

Based on the image below calculate ΣXi, go to n (beginning of the year stuff...)

A professor records the number of classes held in rooms. If these values are presented in a frequency what graph?

Are the data sufficient to conclude the herb has a significant effect on memory? Use a two-tailed test with α = 0.05.

What is the purpose of a t-test?

What is a likely outcome for a hypothesis test if a treatment has a very small effect?

Quiz exam µ = 40 σ = 5, X = 45. On the Stats exam µ = 60 σ = 8, X = 68. What class should Sonja expect better a grade

Why is a negative skew considered 'negative'?

Based on the image below calculate ΣX²

What is the benefit of using a ratio scale?

What does a 95% confidence interval mean?

Based on the image below, calculate Σ(X)²

What is the null hypothesis if a population with a mean of µ = 45 and treatment is expected to decrease in the scores:

Does Quiz aid in studying µ = 10 σ = 2 n= 8. M = 12.5. Conduct the appropriate hypothesis test with α = .05

For this distribution, how many individuals had scores lower than X = 20

Compute and classify Cohen’s d for this study. H0: µ = 70; H1: µ ≠ 70 (two-tailed): zobs < zcrit, retain null

What is the cumulative frequency for the interval 60-63?

Bar graphs are discrete

Which of the following defines a Type II error?

Based on the image below calculate ΣX

What is N?

Which of the following are NOT characteristics of a normal distribution?

What are the two types of categorical scales of measurement?

researcher expects a treatment to increase in the pop mean. using a one-tailed hypothesis test, produces z = –1.85.

For a pop with µ = 78 and σ = 5.60 Abby got a score of 94 and Rachel got 72 What percentage of scores fall between them

we use absolute values with cohens d

Which of the following is an advantage of transforming X values into z-scores?

In a scatterplot for a set of X and Y values, what shape would we expect for: a strong, positive correlation

Based on the image below, find n

Based on the image below: What is the percentile rank for X = 2.5?

a histogram is continuous

A random sample requires that each individual in the population has an equal chance of being selected.

A cohens D of '0.8' represents what kind of effect?

A basketball team averaged μ = 74 of N=25 with SD= 6. In the final game, scoring 90, this is...

Out of N = 5900; 354 abused alcohol, 236 abused drugs (118 used both, same group) Calculate how many used alcohol: