Try this solution (see the attachment, it is consists of 3 steps).
Answer: x=4,y=5
Step-by-step explanation:
The table below summarises the calculation for the standard deviation of x-bar.
![\begin{tabular} {|c|c|c|c|} Drawing (x)&$\bar{x}$&$x-\bar{x}$&$(x-\bar{x})^2\\[1ex] 2,2,2&2&-2.5&6.25\\ 2,2,3&2.3&-2.2&4.84\\ 2,2,5&3&-1.5&2.25\\ 2,2,8&4&-0.5&0.25\\ 2,3,3&2.7&-1.8&3.24\\ 2,3,5&3.3&-1.2&1.44\\ 2,3,8&4.3&-0.2&0.04\\ 2,5,5&4&-0.5&0.25\\ 2,5,8&5&0.5&0.25\\ 2,8,8&6&1.5&2.25\\ 3,3,3&3&-1.5&2.25\\ 3,3,5&3.7&-0.8&0.64\\ 3,3,8&4.7&0.2&0.04\\ 3,5,5&4.3&-0.2&0.04\\ 3,5,8&5.3&0.8&0.64\\ 3,8,8&6.3&1.8&3.24\\ 5,5,5&5&0.5&0.25\\ 5,5,8&6&1.5&2.25\\ 5,8,8&7&2.5&6.25\\ 8,8,8&8&3.5&12.25\\ \end{tabular}](https://tex.z-dn.net/?f=%5Cbegin%7Btabular%7D%0A%7B%7Cc%7Cc%7Cc%7Cc%7C%7D%0ADrawing%20%28x%29%26%24%5Cbar%7Bx%7D%24%26%24x-%5Cbar%7Bx%7D%24%26%24%28x-%5Cbar%7Bx%7D%29%5E2%5C%5C%5B1ex%5D%0A2%2C2%2C2%262%26-2.5%266.25%5C%5C%0A2%2C2%2C3%262.3%26-2.2%264.84%5C%5C%0A2%2C2%2C5%263%26-1.5%262.25%5C%5C%0A2%2C2%2C8%264%26-0.5%260.25%5C%5C%0A2%2C3%2C3%262.7%26-1.8%263.24%5C%5C%0A2%2C3%2C5%263.3%26-1.2%261.44%5C%5C%0A2%2C3%2C8%264.3%26-0.2%260.04%5C%5C%0A2%2C5%2C5%264%26-0.5%260.25%5C%5C%0A2%2C5%2C8%265%260.5%260.25%5C%5C%0A2%2C8%2C8%266%261.5%262.25%5C%5C%0A3%2C3%2C3%263%26-1.5%262.25%5C%5C%0A3%2C3%2C5%263.7%26-0.8%260.64%5C%5C%0A3%2C3%2C8%264.7%260.2%260.04%5C%5C%0A3%2C5%2C5%264.3%26-0.2%260.04%5C%5C%0A3%2C5%2C8%265.3%260.8%260.64%5C%5C%0A3%2C8%2C8%266.3%261.8%263.24%5C%5C%0A5%2C5%2C5%265%260.5%260.25%5C%5C%0A5%2C5%2C8%266%261.5%262.25%5C%5C%0A5%2C8%2C8%267%262.5%266.25%5C%5C%0A8%2C8%2C8%268%263.5%2612.25%5C%5C%0A%5Cend%7Btabular%7D)
Therefore, the standard deviation of x-bar is approximately 1.23.
<span>Successive discounts of 20% and 10% are taken on an item priced at $16.
=> Let's find out how much is the discount in all.
=> 16 dollars * .20 = 3.2 dollars
=> 16 - 3.2 = 12.8 dollars.
then another 10% discount,
=> 12.8 * .10 = 1.28 dollars
=> 12.8 - 1.28 = 11.52 dollars is not the price minus the discounts,</span>
Notice that 25+23+17+14+12+9=100, so among these students there are no 2 studying 2 subjects.
The probabilities of selecting students studying a certain subject are as follows
P(physics)=25/100
P(chemistry)=17/100
P(maths)=9/100
P(sociology)=23/100
P(political sciences)=14/100
P(anthropology)=12/100
since all the sets are disjoint, that is there are no common elements, and since all the students in consideration are enrolled in one these 6 subjects:
P(physics)+P(chemistry)+P(maths)+P(sociology)+P(political sciences)
+P(anthropology)=1
P(a)=P(sociology)+P(political sciences)+P(anthropology)+P(physics)
thus
P(a')=1-P(a)=P(chemistry)+P(maths)=17/100+9/100=26/100=0.26
Answer: 0.26
