Psych 10
A researcher determines that students study an average of 80 minutes per week. Assuming these data are normally distributed and the standard deviation is 20 what is the Z score for students studying 60 minutes per week
-1.0
If the value of this test statistic is in the rejection region then
-P<alpha -The decision is to reject the null hypothesis -The absolute value of this test statistic is larger than the absolute critical value -all of these ALL OF THESE
By definition the probability of an outcome is
-The fraction of times and outcomes likely to occur -The proportion of times and outcome is likely to occur -particularly useful for predicting the likelihood of random events -All of these ALL OF THESE
Our research records the number of bird calls me during an experimental session with Robbins assuming the data are normally distributed N(7.2,0.6) what is the probability that Robin made more than nine bird calls during this experimental session
.0013
A research of records the following response times (in seconds) to a visual stimulus. Assuming these data are normally distributed N (23, 3.1) what is the probability that participants responded in 20 seconds or less (note round Z score to 2 decimal places)
.1660
I research records the body mass index BMI scores for a group of participants participants who score between 25 and 30 on the scale are categorized as overweight assuming the data are normally distributed N(28.4, 1.6) What percentage of participants fell in the overweight category
.8247
A therapist goes to her records and fines at 200 of her 400 patient showed significant improvement in mental health over the past year. Hence the probability of her patients showing significant improvement in mental health is
0.50
The standard normal distribution is normally distributed with a mean of____and a variance of____
0; 1
A professor finds its students scores on the final exam follow a normal distribution N (76, 8) on this example score of 90 is an A what is the Z score for 90 the cut off for an A
1.75
A message for testing a claim or hypothesis about a parameter in a population using data measured in a sample is called
Hypothesis testing
A new pole showed that boaters had no preference for either of the three candidates. In this example the probability of a vote for say candidate A equals
1/3
A research select a sample of 121 participants from the population with the mean of 32 and a standard deviation of 22 what is the standard error of the mean
2.0
In hypothesis testing a researcher decision
All of the
The probability of committing a type one error as stated by____and the probability of committing a type to error is stated by____
Alpha; beta
____Allows researchers to describe how far means scores have shifted in the population or the percentage of variance that can be explained by giving variable
Effect size
A researcher select a sample of 25 participants from the population with me in a 10 and a standard deviation of five what is the probability of selecting a sample me an equal to at least 12
Equal to the probability of selecting the sample mean that is at most equal to 8
Research and find at the average preschool age child drinks 2 cups of milk per day assuming these data I'm normally distributed to the scores for the average cups per day in this example is
Exactly equal to zero
And a sampling distribution of the sample mean is
I distribution of all sample means that could be obtained in samples of a given size from the same population
Research believes that increasing attention given to children will improve me an academic performance therefore the alternative hypothesis should be
I mean academic performance will increase
A researcher obtains Z equals 1.8040 test what is the decision for this test at a .0594 significance
It depends on whether the test is one tail or to tell
Would you be going past describes a P value
It is the probability of obtaining results at least as extreme as observe results
A researcher select sample 49 participants from a population with a mean of 12 and a standard division of 3.5 what is the probability of selecting a sample mean of 13 or larger from this population
Less than 0.03
The criterion for a decision regarding the value stated in a null hypothesis is that by
Level of significance
A research reports at the size of an effect in some population is D equals 0.88 which of the following is an appropriate interpretation for D
Means scores shifted 0.88 standard deviation of the population
I'll research reports that the size of an effect in population A is d = 0.10 and the effect size in population B is D = 0.3 for which population is associated with greater power to detect an effect
Population B
Which of the following is not a characteristic of probability?
Probability is most useful for describing fixed events.
And hypothesis testing a researcher can never
Prove that his or her hypothesis is correct
A researcher Celexa sample of 32 students from the school population with the mean IQ of 100 and standard deviation of 12 she determines at the mean IQ and the sample is 104 assuming she competes a Z test at 8.05 level significance what is the decision for a two tail test
Reject the null hypothesis; I can scores in the sample are significantly higher than those in the population
What values are distributed along the X axis for a sampling distribution of the sample mean
Sample means
The normal distribution is symmetric which means that
Score is above the mean are distributed the same as score is below the mean
Supposed to researcher want to make sure that the probability of committing a type one error is less than 5% how can the researcher control for this
Set the Alpha level at .05
The first step to hypothesis testing requires that a researcher
State the hypothesis
Which of the following statements regarding the null hypothesis is true
The null hypothesis always make statements about a population parameter
The normal distribution has all of the following characteristics except that
The total area under the curve is greater than 1.0
The main can take on any value and the standard deviation can take on any positive value. Therefore
There are an infinite number of possible normal distribution's
A researcher obtain a Z equals 2.04 for the test what is the decision for this test at 8.05 level of significance
To reject the no hypothesis either for a new one tail or two tail 10
A professor finds out the average SAT score among all students attending college is 1150 sigma equals 150 he pulls his class of 25 students and find that the average SAT score is 1200 suppose he competes Z test at 8.05 level of significance what is his decision
To reject the null hypothesis for a one tail test but to retain the null hypothesis for it to tail test
The unit of measurement distributed along the X axis of a standard normal distribution is referred to as a
Z score
