statistics

------ 1 -------
Let z=
2.33 1.36 3.33 2.56 2.39 1.91 0.79 1.84 0.47 0.33 0.53 4.35 0.01 0.63 3.73 1.92 7.58 1.04 1.56 0.00
# Test visually whether z is normally distributed. Attach the plot and show your reasoning for the decision.

------- 2 -------
# Test the null hypothesis Ho:"z is normally distributed". 
# Determine the p-value. Can the null hypothesis be rejected at the significance level 0.005?

------- 3 -------
Let x=
3.02 5.61 -0.87 -0.22 10.45 1.58 11.06 8.12 5.31 1.28

Let y=
7.18 3.02 7.51 4.38 8.44 7.62 11.51 6.33 6.10 6.01

Note: y and x are not paired.

# Test the null hypothesis Ho:"mean of y is equal to 9.2".  
# Can the null hypothesis be rejected at the significance level 0.05?

------- 4 ------- (use data from previous question)
# Test the null hypothesis Ho:"mean of y is greater than the mean of x by 3 or more".  
# Can the null hypothesis be rejected at the significance level 0.05?

------- 5 ------- (use data from previous question)
# Can one determine the Pearson correlation coefficient between y and x ? If yes, what is the value; if no, why no? 

------- 6 ------- 
# Let A=last 30 daily closing prices of SU and B=last 30 daily closing prices of COS on Toronto Stock Exchange. Determine the Pearson correlation coefficient between A and B. Can one at a significance level 0.05 claim that the correlation coefficient is different from zero?