<span>Answer:
MgF2 ====⇒ Mg+2 + 2F-
Ksp = [Mg+2][F-]^2
Let S = molar solubility of MgF2
[Mg+2] = S ; [F-] = 2s
Since the [F-] is initially 0.40 M, then [F-] = 0.40 + 2S
6.4 x 10^-9 = (S) (0.40 + 2S)^2 ; one can neglect the 2S in the 0.40 + 2S expression since it is very, very small compared to the 0.40 already present.
6.4 x 10^-9 = S(0.40)^2
S = 4.0 x 10^-8
Molar solubility = 4.0 x 10^-8</span>
Answer:

t = 2.2450
d. 0.264
Step-by-step explanation:
The null hypothesis is:

Alternative hypothesis;

The pooled variance t-Test would have been determined if the population variance are the same.



The t-test statistics can be computed as:



t = 2.2450
Degree of freedom 
df = (8-1)+(8-1)
df = 7 + 7
df = 14
At df = 14 and ∝ = 0.05;

Decision Rule: To reject the null hypothesis if the t-test is greater than the critical value.
Conclusion: We reject
and there is sufficient evidence to conclude that the test scores for contact address s less than Noncontact athletes.
To calculate r²
The percentage of the variance is;




Answer:
-765
Step-by-step explanation:
-2-7 * 109
-2 - 763
-765
It would be zero because x can’t be less or more in this particular situation.