We are on our fourth day of reviewing for the exam , and today we've chose to review STATS.
Statistics Exam Reviw
The general learning outcomes are
- Find the population standard deviation of a data set using tech.
- Use z-scores to solve problems
Some Tips and Tricks.
- Can you find the mean and standard deviation of :
A. Ungrouped Data?
- single data set
-**stat- calc- 1 var stats L1
B .Grouped Data?
- 2 data sets (one set of boundaries and one set of frequencies)
- **stat calc 1-Var stats L1, L2
- boundaries * first list
- frequencies * second list
- Z-scores (& Normal Distributions)
*** 68%-95%-99.7%
z= (the mark - mean )/ standard deviation
A. normal cdf ( lowest score, highest score, mean, standard dev.)
OR
normal cdf (lowest zscore, highest z score)
B. www.Ronblond.com
*Record what your inputs are.. forgetting to write your inputs WILL GET YOU NO POINTS.
C. "Stats spreadsheet" on the network
* This sheet will do any kind of question that will get thrown at you on the exam. ALso, record your inputs, screen shots aren't a bad idea either. - Binomial distributions/ conifidence intervals
A. mean = n*p
standard dev. = n*p*q ------> provided the distribution is binomial
(( p is "probablity" of success
q= "probability of failure"
n= number of items in a data set.))
B. Binompdf or Binomcdf*** unlikely to see on exam.
( # of prob trials, prob of success, no. of successes)
pdf = implies... ""Exactly this many successes""
cdf = imples... ""At most this many successes""
So, P(AT LEAST) = 1- P(at most)
C.Confidence Intervals
To receive full marks... your answer should look like this:
- 1propZInt
x: __
n: __
C-level: ___
*Calculator default for the interval is decimals/ percentages
- must be converted if required
( p-low * n , p-high * n )
**** As level of confidence increases size of interval Also increases.
Study hard, it'll be worth it =)!
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