PSYC 510
HOMEWORK: Z-SCORES AND PERCENTILES TEMPLATE
This assignment is worth a total of 60 points.
• Content: point values vary but are indicated in the template and total 45 points.
• Format: point values vary but are indicated in the template for 10 pts. The remaining 5
pts are for placing answers in the correctly designated spots within the template in a clear
and easy to read format (e.g., all fit within the visible screen on the page) and uploading
it in an approved format (word or PDF). Thus, the maximum is 15 points for format.
Here is memory data from 25 students. Create an SPSS data file using this data.
8 6 7 5 5
5 6 8 5 3
6 9 5 9 7
6 5 6 4 8
8 7 10 6 6
1. Name the variable “Memory” in Variable View, and set the scale of measurement. Run
descriptive statistics to obtain the needed mean and standard deviation and other
information to determine whether the data is normally distributed. Make sure to “save
standardized values” when doing so. Copy / Paste the output here, formatting using
professional conventions, numbering it as Table 1 and giving it an appropriate title (no
Note needed). (4 pts content / 3 pt format)
Table 1
Descriptive Statistics for Memory
2. Create an appropriate figure to examine the distribution of memory scores in the sample
(make sure both axes titles are in Title Case!). Number it Figure 1 and create an
appropriate title. In the Note section, using both a visual inspection of the data and a
skewness statistic to discuss whether the distribution is normal. Make sure all components
are formatted using APA conventions. (4 pts content / 3 pts format)
Page 1 of 5
, PSYC 510
Figure 1
Changes in Memory
Note: Figure 1 shows a normal symmetric distribution of memory, with a standard deviation of
1.68325. Along with this, we can see that skewness is .273 and standard error of skew is .464,
which also correlates with normal symmetric distribution.
3. Determine whether memory scores in this sample are normally distributed. State whether it
is normally distributed and what information you used to determine this. (2 pts)
One way to determine whether the memory scores in the same are normally distributed is
to examine the skewness of data. If we examine Table 1 from question 1, we can see that
skewness is .273. As the skewness is between -1 to 1, we can determine that this value is
closer to 0, thus indicating normal distribution.
4. Write a brief description of the memory scores obtained from this sample as you would in
a Method section of a research report. Use proper APA format as shown in previous
weeks. (4 pts content / 2 pts format)
For this study, 25 student participants provided 25 memory scores which ranged from 3
-10. The mean of the data was 6.40 and a standard deviation was 1.68, which correlated to
normal distribution.
5. Continuing to use this dataset, go to Variable View, create a third variable and name it
“percRank”. Have SPSS compute the percentile ranks based on the normal distribution,
Page 2 of 5
HOMEWORK: Z-SCORES AND PERCENTILES TEMPLATE
This assignment is worth a total of 60 points.
• Content: point values vary but are indicated in the template and total 45 points.
• Format: point values vary but are indicated in the template for 10 pts. The remaining 5
pts are for placing answers in the correctly designated spots within the template in a clear
and easy to read format (e.g., all fit within the visible screen on the page) and uploading
it in an approved format (word or PDF). Thus, the maximum is 15 points for format.
Here is memory data from 25 students. Create an SPSS data file using this data.
8 6 7 5 5
5 6 8 5 3
6 9 5 9 7
6 5 6 4 8
8 7 10 6 6
1. Name the variable “Memory” in Variable View, and set the scale of measurement. Run
descriptive statistics to obtain the needed mean and standard deviation and other
information to determine whether the data is normally distributed. Make sure to “save
standardized values” when doing so. Copy / Paste the output here, formatting using
professional conventions, numbering it as Table 1 and giving it an appropriate title (no
Note needed). (4 pts content / 3 pt format)
Table 1
Descriptive Statistics for Memory
2. Create an appropriate figure to examine the distribution of memory scores in the sample
(make sure both axes titles are in Title Case!). Number it Figure 1 and create an
appropriate title. In the Note section, using both a visual inspection of the data and a
skewness statistic to discuss whether the distribution is normal. Make sure all components
are formatted using APA conventions. (4 pts content / 3 pts format)
Page 1 of 5
, PSYC 510
Figure 1
Changes in Memory
Note: Figure 1 shows a normal symmetric distribution of memory, with a standard deviation of
1.68325. Along with this, we can see that skewness is .273 and standard error of skew is .464,
which also correlates with normal symmetric distribution.
3. Determine whether memory scores in this sample are normally distributed. State whether it
is normally distributed and what information you used to determine this. (2 pts)
One way to determine whether the memory scores in the same are normally distributed is
to examine the skewness of data. If we examine Table 1 from question 1, we can see that
skewness is .273. As the skewness is between -1 to 1, we can determine that this value is
closer to 0, thus indicating normal distribution.
4. Write a brief description of the memory scores obtained from this sample as you would in
a Method section of a research report. Use proper APA format as shown in previous
weeks. (4 pts content / 2 pts format)
For this study, 25 student participants provided 25 memory scores which ranged from 3
-10. The mean of the data was 6.40 and a standard deviation was 1.68, which correlated to
normal distribution.
5. Continuing to use this dataset, go to Variable View, create a third variable and name it
“percRank”. Have SPSS compute the percentile ranks based on the normal distribution,
Page 2 of 5
