Answer:
Option (C)
Step-by-step explanation:
In the given circle, AB is a chord passing through the center O.
Therefore,chord AB is a diameter of the circle and OC is the radius.
AO = OB = OC
OC⊥AB, and length of OC = 7 cm
By applying Pythagoras theorem in right ΔBOC,
BC² = OC² + OB²
BC =
=
=
≈ 9.9 units
Therefore, Option (C) will be the answer.
Answer:
Given:
Sham: n= 20, x=0.44, s=1.24,
Magnet:n= 20, x =0.49, s= 0.95
For Sham:
Sample size, n = 20
Sample mean = 0.44
Standard deviation = 1.24
For Magnet:
Sample size = 20
Sample mean = 0.49
Standard deviation = 0.95
The null and alternative hypotheses:
H0: s1²=s2²
H1: s1² ≠ s2²
a) To find the test statistics, use the formula:
Test statistics = 1.7037
b) P-value:
Sham: degrees of freedom
Magnet: degrees of freedom
The critical values:
[Za/2, df1, df2)], [(1 - Za/2), df1, df2]
The rejection region:
Reject H0, if F < 0.3958 or if F > 2.526
c) Conclusion:
Since the critical values of test statistic is between (0.3958 < 1.7037 < 2.526), we fail to reject null hypothesis H0.
There is insufficient evidence to to support the claim that those given a sham treatment have reductions that vary more than those treated with magnets