The critical values are fixed values which can be
obtained from the standard t crit
tables. We can find the critical value tc when the degrees of freedom
and confidence level are given. The degrees of freedom is simply:
Degrees of Freedom = Number of samples – 1
Degrees of Freedom = 19 – 1
Degrees of Freedom = 18
From the t critical tables, the tc corresponding to Degrees
of Freedom equal to 18 and Confidence level equal to 95% is as follows:
tc = 2.101
Therefore this means that any t value beyond 2.101, we already
reject the null hypothesis.
So it seems as if the first problem is asking this:

.
If x=0.15, then 11/15*(0.15) is 0.11 or 11/100.
The second problem is asking:

To solve algebraically, you want to get rid of the denominators under the x's. To do so, you want to multiply by the Least Common Multiple (LCM) of the denominators. For 3 and 4, the LCM is 12. Multiply everything by 12 to get:
3x+6=4x+2
Now, solve for x
Subtract 4x from both sides:
-x+6=2
Subtract 6 from both sides:
-x=-4
Multiply by -1 on both sides:
x=4.
Answer: False X+X is not equal to X^2 X can be any number
Step-by-step explanation: