# Various Math statistics Questions

1. Find range, variance, and standard deviation. Identify one reason why the standard deviation from this sample might not be a good estimate of the standard deviation for the population of adults.

56 54 64 67 58

2. Below are 36 sorted ages of an acting award winner. Find p60 method:

16 23 24 26 30 32 32 34 37 40

40 42 43 44 48 49 54 54 58 59

61 61 62 64 65 66 67 68 69 70

70 72 72 73 77 78

P60=____

3. Statistics are sometimes used to compare or identify authors of different works. The length of the first 10 words in a book by Terry are listed with the first 10 words in a book by David. Find the mean & median for each of the two samples then compare the two set of results.

Terry 1 2 6 2 5 4 1 1 11 1

David 3 1 2 2 2 5 3 2 2 5

The mean # of letters per word in Terry's book is___

4. A) In a poll 84% of 1037 surveyed adults said that pesticides are quite annoying. What is the actual number of adults who said that pesticides are "quite annoying"?

B) Among the 1037 surveyed adults, 102 said that pesticides are "not at all annoying" What is the percentage of people who chose "not at all annoying.?

A) What is the actual number of adults who said that pesticides are "quite annoying,___

5) A particular group of men have heights with a mean of 174cm and a standard deviation of 8cm. Bill had a height of 178cm.

a) what is the postive difference between Bill's height and the mean?

b) how many standard deviations is that (the difference found in part (a) )?

c) Convert Bill's height to a z score?

d) If we consider usual heights to be those that convert to z scores between -2 & 2 is Bill's height usual or unusual?

6) Listed below is numbers of words defined on those pages. Find the mean median mode and midrange. Dictionary has 1,452 pages with defined words. Estimate the total number of defined words in dictionary. Is that estimate likely to be an accurate estimate of the number of words in the English language?

#### Solution Preview

1. mean=(56+54+64+57+68)/5=59.8

variance=[ (56-59.8)^2+ (54-59.8)^2+ (64-59.8)^2+ (57-59.8)^2+ (68-59.8)^2]/(5-1)=30.2

sd=sqrt(30.2)=5.50

standard deviation from this sample might not be a good estimate of the standard deviation for the population of adults because the sample size is too SMALL (here ...

#### Solution Summary

The solution gived detailed steps on solving various questions on the descrptive statistics. All formula and calcuations are shown and explained.