1. The following scatter diagrams were drawn by a student

The values were:

1. -0.12
2. 87
3. -0.81

Write down which value corresponds to each scatter diagram. Give a reason for your answer.

1. An on-line music service company wants to know (for the purposes of designing a marketing campaign) if customer age is important in deciding to subscribe, and, if so, which age groups are most likely to subscribe to its services. The company has gathered a random sample of 1000 people from the population and asked each person whether he or she would subscribe to the service. The company knows which age group the person falls into under 18 years of age, 18 - 34 years of age, and 35 years or older. What is the chi-square statistic?

	Under 18	18 - 34	35 and over	Total
Yes	120	262	237	619
No	41	103	237	381
Total	161	365	574	1,000

1. The table below provides with the weekly returns for Bitcoin and Ethereum for 20 consecutive weeks.

Date	Bitcoin	Ethereum
06/07/2020	2.2%	6.4%
13/07/2020	-1.0%	-1.5%
20/07/2020	7.8%	29.8%
27/07/2020	11.6%	19.7%
03/08/2020	5.6%	5.5%
10/08/2020	1.9%	10.9%
17/08/2020	-1.9%	-9.8%
24/08/2020	0.4%	9.5%
31/08/2020	-12.2%	-17.5%
07/09/2020	0.4%	3.5%
14/09/2020	6.0%	1.5%
21/09/2020	-1.5%	-3.7%
28/09/2020	-0.8%	-1.2%
05/10/2020	6.5%	6.2%
12/10/2020	0.9%	0.8%
19/10/2020	13.5%	7.4%
26/10/2020	5.4%	-2.4%
02/11/2020	12.7%	14.4%
09/11/2020	1.4%	2.1%
12/11/2020	3.4%	0.0%

a. Calculate the standard deviation of Bitcoin and Ethereum's returns

b. Calculate the covariance between the returns on these two cryptocurrencies

c. Calculate the correlation between returns

d. What kind of linear correlation exists between the variables?