z-scores
z-scores
continued..
SEm/ Confidence Intervals
Miscellaneous
Computer Day #1
100
What is the definition of a z-score?
A single datapoint in standard deviation units from the mean.
100
What percent of scores fall within 1 standard deviation?
68%
100
What is sampling?
The process of taking a smaller group of participants/scores from a larger population.
100
Once you have a mean calculated in a cell on excel, how can you quickly get the means for the rest of the row?
Click the black cross on the corner of the cell and drag it across the row.
100
What do you always do before clicking fx ?
Select an empty cell.
200
What is the equation to calculate a z-score?
z=(x-M)/S
200
What percentage of scores fall within 2 standard deviations?
95%
200
What does standard error measure?
Standard error measures the variability of a distribution of means
200
Suppose a child weighs 55.00 pounds and the mean for her age, height and gender is 60.00 pounds and the standard deviation is 5.00. What is the z-score?
-1
200
What are the steps in which you find the mean, median, and mode?
Select an empty cell, click Fx, click "average,median or mode", highlight numbers, click enter.
300
Calculate a z-score for: X= 60 , M= 70, S=10
z-score is -1
300
Assume that an exam has a mean of 55, a standard deviation of 6, and has a normal distribution. If someone’s z-score is -1.66, then s/he ranks in the ____th percentile.
5th
300
Fill in the blanks: The _______ the sample, the ______ the standard error of the mean.
larger, smaller
300
In a normal distribution with M=70 and S=10 between what two values does the middle 68% of a population lie according to the rule?
between 60 and 80
300
What do you need to find before you do the range in excel?
the maximum and minimum
400
If M=511.2 and S=20.28 and Sarah has a raw score of 460, what is the value of her z-score?
-2.52
400
What is the equation to solve for X?
X=z(S)+M
400
What does a confidence interval do?
Provides a range for estimating the true mean of the population based on your sample.
400
True or False: It is possible to completely avoid unbiased samples.
False
400
How do you find standard error in excel?
select an empty cell, type "=", then select standard deviation cell, type "/", click fx for "sqrt", then put n in parentheses and click enter.
500
Assume that an exam has a mean of 55, a standard deviation of 6, and has a normal distribution. If someone scored a 63, what is their percentile rank?
91st
500
If z=2.33, M=1020, S=500, What is the actual raw score on the SAT?
2185
500
How do we calculate Standard Error of the mean?
SEm= SD / square root of n
500
Fill in the blanks: The ______ the variability in the population, the ______ the SEm
lesser, smaller
500
How do you add 68% confidence intervals on your graph?
click green plus sign, select error bars, then click more options, click custom, select specify value, delete components already in the boxes, copy and paste standard errors, and same for negative then click enter.
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