Inferential statistics deal with:
If you have a negative z-score it will be below the mean.
Which of the following is not a conditional probability?
What is the probability 1 in 12 expressed as a percentage?
In order to use standard normal distribution you need to transform the scores in the sample to the standard normal scores. This is achieved by which of the following? What is the result called?
Convert the age of a 32 year old to a z-score if the mean of the set of ages is 40 years and the standard deviation of age is 6 years.
The mean of a set of IQs is 100 and the standard deviation is 15. The z score for one student is +2.2 Using the necessary z-score table in appendix 1, what does this mean?
You have the IQs of a set of people. The mean of these IQs is 100. The standard deviation is 15. One student scored 90 on the test. This produced a z-score of -0.67 or -0.7 to 1 decimal place. Using the z-score table in appendix 1, what does this mean?
Suppose that some assessment results for two types of offenders (sex offenders and violent offenders) were 60 and 50 respectively. Which type of offender did better in comparison to other offenders on the treatment course and which may need further treatment? The group means and SDs are 50 and 9 for sex offenders and 45 and 3 for violent offenders.
We do not know whether the pattern of results found in our samples accurately reflects what is happening in the population or if it is the result of _____ error.
Normal distribution theory tells us that for large samples, 95% of sample means lie within how many standard deviations above and below the population mean?
Consider the following data to answer the next 3 questions.
You have the following sample data; a sample size of 7, a mean of 8 and a standard deviation of 4.2. From this, what is the standard error?
You still have the same data (a sample size of 7, a mean of 8 and a standard deviation of 4.2) plus the standard error. Next how would you calculate the 95% confidence intervals?
Finally, you still have the same data (a sample size of 7, a mean of 8 and a standard deviation of 4.2) plus the standard error and you know how to calculate the 95% confidence interval. Thus what is the 95% confidence interval?
In another study you have a standard deviation of 12, a mean of 20 and a sample size of 50. What is the standard error?
The standard error has been calculated as 2.6 and the sample mean is 10.00. Thus the 95% confidence interval lies between:
To calculate confidence intervals we need make use of:
A sample mean is a ____ estimate and we do not know how close it is to the population mean.
Which of the following type of graph can display confidence intervals?
Sampling distributions tend to be what in shape?
Which of the following is the correct statement?
In error bar charts the larger the confidence interval the _____ the line is through the mean.
There is substantial overlap between two sets of confidence intervals on an error bar chart. The chart shows confidence intervals for boys and girls on a depression questionnaire. What could we make of this?