Evaluate descriptive statistics Discussion
The calculations are the easy part. What the assignment is testing is whether you can read a difference in spread across unequal groups without over-claiming from it.
Editorial process
Last reviewed · August 22, 2026
The spread across groups is what the assignment is about
The arithmetic is the smallest part of this. Get it right by using the sample rather than the population formula for variance and standard deviation unless the data are the whole population, which they are not here, and notice that the mode is often absent or meaningless in continuous data, so reporting no mode is a legitimate finding rather than an error. Then look at the relationship between the mean and the median within each group, because a mean well above the median indicates a right-skewed distribution, and that in turn tells you which measure of centre actually represents the group. Reporting a mean for a visibly skewed group without saying so is the most common way to lose marks here. Note the mode too: with continuous incidence data there is often no repeated value at all, and saying so plainly is better than forcing one out of rounded figures.
The interpretation is where the assignment becomes about health care rather than about arithmetic, and it needs care. Comparing standard deviations across the racial and ethnic groups is the interesting comparison, because a larger spread means the group is less homogeneous on this measure, which usually reflects real heterogeneity in a population that a category has flattened. Two cautions belong in the evaluation. Group sizes differ, so a small group will produce less stable estimates and a wider range simply through having fewer observations, which is a property of the sample rather than of the population. And racial and ethnic categories in cancer surveillance are administrative groupings that combine very different populations, so a difference between them is a signal to investigate rather than an explanation. Say what you would want next: age-adjusted rates, stage at diagnosis, and access measures, because raw descriptive statistics cannot separate biology from access.
Likely learning objectives
- Use the correct variance formula for sample data.
- Read skew from the relationship between mean and median.
- Compare spread across groups while accounting for unequal group sizes.
- Treat racial and ethnic categories as administrative groupings rather than explanations.
Assignment instructions
Read the full question
Review every instruction before using the planning guidance that follows.
There is often the requirement to evaluate descriptive statistics for data within the organization or for health care information. Every year the National Cancer Institute collects and publishes data based on patient demographics. Understanding differences between the groups based upon the collected data often informs health care professionals towards research, treatment options, or patient education. Using the data on the “National Cancer Institute Data” Excel spreadsheet, calculate the descriptive statistics indicated below for each of the Race/Ethnicity groups. Refer to your textbook and the Topic Materials, as needed, for assistance in with creating Excel formulas. Provide the following descriptive statistics: Measures of Central Tendency: Mean, Median, and Mode Measures of Variation: Variance, Standard Deviation, and Range (a formula is not needed for Range). Once the data is calculated, provide a 150-250 word analysis of the descriptive statistics on the spreadsheet. This should include differences and health outcomes between groups. APA style is not required, but solid academic writing?is expected. This assignment uses a rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.
Course-wide instructions that accompany this question
You must proofread your paper. But do not strictly rely on your computer’s spell-checker and grammar-checker; failure to do so indicates a lack of effort on your part and you can expect your grade to suffer accordingly. Papers with numerous misspelled words and grammatical mistakes will be penalized. Read over your paper – in silence and then aloud – before handing it in and make corrections as necessary. Often it is advantageous to have a friend proofread your paper for obvious errors. Handwritten corrections are preferable to uncorrected mistakes. Use a standard 10 to 12 point (10 to 12 characters per inch) typeface. Smaller or compressed type and papers with small margins or single-spacing are hard to read. It is better to let your essay run over the recommended number of pages than to try to compress it into fewer pages. Likewise, large type, large margins, large indentations, triple-spacing, increased leading (space between lines), increased kerning (space between letters), and any other such attempts at “padding” to increase the length of a paper are unacceptable, wasteful of trees, and will not fool your professor. The paper must be neatly formatted, double-spaced with a one-inch margin on the top, bottom, and sides of each page. When submitting hard copy, be sure to use white paper and print out using dark ink. If it is hard to read your essay, it will also be hard to follow your argument.
Turn the brief into deliverables
- 01Mean, median and mode for each group.
- 02Variance, standard deviation and range for each group.
- 03A note where the mode is absent or uninformative.
- 04A skew observation from the mean and median relationship.
- 05A comparison of spread across groups.
- 06Cautions about group size and about category meaning.
- 07A statement of what further data would be needed.
Compute, then compare, then interpret cautiously
Getting the calculations right
Compute the six statistics per group with the correct formulas.
What the assessor is likely looking for
The sample variance formula used, with the reason stated.
Reading the shape
Use the mean and median relationship to identify skew in each group.
What the assessor is likely looking for
A skew judgement made from the two measures rather than asserted.
Comparing spread
Compare standard deviations and ranges across the groups.
What the assessor is likely looking for
Range identified as the most sample-size-sensitive measure.
Two cautions
Address unequal group sizes and the meaning of the categories.
What the assessor is likely looking for
A category treated as a grouping to be investigated, not a cause.
What you would want next
Name age adjustment, stage at diagnosis and access measures.
What the assessor is likely looking for
A specific further measure that would separate competing explanations.
Where the measures and the cancer data are documented
Recommended databases
- SEER
- NCBI Bookshelf
- PubMed Central
- GCU Library
Search sequence
- 1.Confirm the sample versus population formula before calculating.
- 2.Look at how cancer surveillance reports rates, particularly age adjustment.
- 3.Read a source on descriptive statistics and distribution shape.
- 4.Check how the data source defines its race and ethnicity categories.
Reference shortlist
These are authoritative starting points, not a ready-made bibliography. A qualified reviewer must confirm that each source fits the assignment and supports the claim beside which it is cited.
Exploratory Data Analysis: Frequencies, Descriptive Statistics, Histograms, and Boxplots
StatPearls, NCBI Bookshelf · 2026
Descriptive statistics and distribution shape, for the calculation and the reading.
SEER Cancer Stat Facts
National Cancer Institute Surveillance, Epidemiology, and End Results Program · 2025
Cancer surveillance data, for how these figures are normally reported.
Hypothesis Testing, P Values, Confidence Intervals, and Significance
StatPearls, NCBI Bookshelf · 2023
Inference basics, for why descriptive statistics alone cannot support a comparison.
Social Determinants of Health
Office of Disease Prevention and Health Promotion · 2024
The determinants framework, for the access explanation the data cannot rule out.
Epidemiology Morbidity And Mortality
StatPearls, NCBI Bookshelf · 2023
Morbidity and mortality measurement, for age adjustment and rate construction.
Before you submit this assignment
Common mistakes
- Using the population variance formula on sample data.
- Reporting a mean for a clearly skewed group without noting the skew.
- Attributing a difference between groups to the category itself.
- Ignoring that a small group produces less stable estimates.
- Presenting the numbers without any interpretation.
Submission checklist
- Did you use the sample formula for variance and standard deviation?
- Have you compared mean and median within each group?
- Is the spread comparison accompanied by the group sizes?
- Have you avoided treating the category as the explanation?
- Is there a statement of what you would want to see next?
Use this guide to plan and review your own work. Follow your institution's rules and read Brinevia's academic-integrity policy.
Written by
Maren Caldwell
MSN, RN, CNE
Medical-surgical nursing, pharmacology and NCLEX preparation
Maren is a registered nurse with over 15 years of clinical and educational experience in medical-surgical nursing. She writes on NCLEX preparation, patient care fundamentals, pharmacology and evidence-based practice.
Reviewed by
Dr. Tessa Redmond
DNP, RN, CNE
Evidence-based practice and clinical education
Tessa is a doctorally-prepared nurse educator. She reviews Brinevia content for clinical accuracy and alignment with current evidence-based guidelines.