Answer:
A. No, this is not a valid inference because he asked only 20 families
Step-by-step explanation:
You cannot assume that those are the only families that would want to go; you have to ask all the families.
The answer is (LxW) every square is (LxW) it does not matter what size.
The solution would be like this for this specific problem:
H0: p = p0, or <span>
H0: p ≥ p0, or
H0: p ≤ p0 </span>
find the test statistic z
= (pHat - p0) / sqrt(p0 * (1-p0) / n)
where pHat = X / n
The p-value of the test is
the area under the normal curve that is in agreement with the alternate
hypothesis. <span>
H1: p ≠ p0; p-value is the area in the tails greater than |z|
H1: p < p0; p-value is the area to the left of z
H1: p > p0; p-value is the area to the right of z </span>
Hypothesis equation:
H0: p ≥ 0.67 vs. H1: p
< 0.67
The test statistic is: <span>
z = ( 0.5526316 - 0.67 ) / ( √ ( 0.67 * (1 - 0.67 ) / 38 )
z = -1.538681 </span>
The p-value = P( Z < z
) <span>
= P( Z < -1.538681 )
<span>= 0.0619</span></span>
The proportion would be 1/3 and x/9. Cross multiplication creates 3x=9. Divide both sided by three, and there are 3 trombones in the orchestra.