Statistics and Probability Answers

Data Set: Sample of 7 different species of fish has been taken and their weight in grams, lengths (vertical, diagonal, cross given as length 1, length 2 and length 3 respectively), height and width in cm is given below:

Species

Weight

Length1

Length2

Length3

Height

Width

Bream

725

31.8

35

40.9

16.36

6.0532

Bream

720

32

35

40.6

16.3618

6.09

Bream

714

32.7

36

41.5

16.517

5.8515

Species

Weight

Length1

Length2

Length3

Height

Width

Bream

725

31.8

35

40.9

16.36

6.0532

Bream

720

32

35

40.6

16.3618

6.09

Bream

714

32.7

36

41.5

16.517

5.8515

a. Find the mean and standard deviation for each type of fish for every variable.

b. If you need to choose a fish on the basis of weight, which fish you choose?

c. Find mean, median, quartiles for the entire data set for each variable.

(a) The supermarket statistician realized that there was a considerable range in the spending

power of its customers. Even though the overall spending seemed to have increased the

high spenders still spent more than the low spenders and that the individual increases would

show a smaller spread. In other words these two populations, ‘before’ and ‘after’, and not

independent.

Before the next advertising campaign at the supermarket, he took a random sample of 10

customers, Α to J , and collected their till slips. After the campaign, slips from the same

10 customers were collected and both sets of data recorded. Using the paired data, has there

been any mean change at a 95% confidence level?

A B C D E F G H I J

Before 42.30 55.76 32.29 10.23 15.79 46.50 32.20 78.65 32.20 15.90

After 43.09 59.20 31.76 20.78 19.50 50.67 37.32 77.80 37.39 17.24