100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Statistics final wgu academy 2024/2025(100% verified) A+ score assured £9.21   Add to cart

Exam (elaborations)

Statistics final wgu academy 2024/2025(100% verified) A+ score assured

 22 views  2 purchases
  • Module
  • Institution

Statistics final wgu academy 2024/2025(100% verified) A+ score assured

Preview 2 out of 5  pages

  • March 27, 2024
  • 5
  • 2023/2024
  • Exam (elaborations)
  • Questions & answers
avatar-seller
Statistics final wgu academy

nominal variables - ANSCategorical variables that there is no natural order among the
categories

ordinal variable - ANSCategorical variables where there is natural order among the
categories (low-high)

interval - ANSA measurement which makes sense to talk about the difference between
values but not the ratio between values

ratio - ANSQuantitive variables where is makes sense to talk about the difference in ratios.
(Income, weight)

In ratios: - ANSValue 0 means the absence of quantity (income $0)

Distribution of a Variable - ANSTells us what values the variables take and how often they
take those values

In intervals: - ANSVale 0 does not mean the absence of value (temp = 0F)

Pie charts - ANSEmphasize how the different categories relate to the whole

Bar charts - ANSEmphasize how the different categories compare with each other

Histogram - ANSBreaking the range of values into intervals and count how many
observations fall into interval.

Stemplot(stem and leaf plot) - ANSGraphical display of quantitive data. Data is spread into
"stem" and "leaf". It retains the data and sorts.

Boxplot - ANSGraphically represents the distribution of a quantitive variable. Visually
displays the five number summary and the observations classified as a suspected outlier.

Measures of Center - ANSMode, mean, and median.

Mode - ANSThe most commonly occurring value. Can be unimodal or bimodal

Mean - ANSThe average of a set of observations.
The sum of observations divided by the number of observations. (x bar)

Median - ANSThe midpoint of the distribution. (M)

Measures of soread - ANSRange, inter quartile range (IQR), standard deviation

, How to find the median - ANS-order the data smallest to largest
-if the number(n) of observations is odd (n+1)/2nd spot
-if the number(n) of observations is even we have two n/2 = spot & n/2 + 1 = spot

Measure of center that is sensitive to outliers - ANSMean

Measure of center that is not sensitive to outliers - ANSMedian

Symmetric distributions - ANSMean and median will be approximately equal

skewed right - ANSMean will be greater than the median

skewed left - ANSMean will be less than the median

range - ANSThe exact distance between the smallest data point and the largest. The most
intuitive measure of variability.

Inter-Quartile Range (IQR) - ANSMeasures the variability of a distribution by giving us the
range covered by the MIDDLE 50% of the data.
- Step 1: Arrange the data in increasing order, and find the median
- Step 2: Find the median of the lower 50% of the data = 1st quartile (Q1)
- Step 3: Repeat this again for the top 50% of the data = 3rd quartile (Q3)
- Step 4: The middle 50% of the data falls between Q1 and Q3. Therefore: IQR = Q3 - Q1

Note: When finding the median of an odd number of data items, it is not included in either
the bottom or top half of the data; when median is even, the data are naturally divided into
two halves.

When should the IQR be used? - ANSOnly when the median is used as a measure of center.

When should an outlier be kept in the data? - ANS-when the outlier is produced by the same
sort of physical or biological process as the rest of the data.
-the outlier is expected to eventually occur again

five number summary - ANSmin, Q1, median, Q3, max

standard deviation - ANSQuantifies the spread of a distribution by measuring how far the
observations are from their mean. ( gives the average distance between a data point and the
mean (xbar)

how to find standard deviation? - ANS-find the mean
-find deviations from the mean (xbar - 2,3,4,5 etc)
-square each deviation
-add all squared deviations then divide them by n - 1 (sample size minus 1)
-find square root of new total, this is the standard deviation

Variance of data - ANSThe average of the squared deviations

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller Tutor96. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £9.21. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

76449 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling

Recently viewed by you


£9.21  2x  sold
  • (0)
  Add to cart