Mathematically, 10 times.
Realistically, you can't tell.
Answer:
The first one, 10 15 20
45 -5 -35
55 25 -15
Step-by-step explanation:
A. Interviews of random teens at a rock concert
These teens are all fans of the same music because they are attending the same concert. They cannot accurately represent all teens music choices because they are all bias toward the same music style. They are especially excited about it at the concert so responded are even more skewed.
Answer:

Step-by-step explanation:
<em>Step 1: Define significance level</em>
In this hypothesis testing problem, significance levels α is selected:
, the associated z-value from Laplace table:
Φ(
) = α - 
=>
= 
<em>Step 2: Define null hypothesis (</em>
<em>) and alternative hypothesis (</em>
<em>)</em>
: rate of flu infection
= 8.3% or 8.3/100 = 0.083
: rate of flu infection
< 8.3% or 8.3/100 = 0.083
<em>Step 3: Apply the formula to check test statistic:</em>

with
is actual sampling percent,
is rate of flu infection of
,
is number of samples.
The null hypothesis will be rejected if 
<em>Step 4: Calculate the value of K and compare with </em>
We have 
=>This is good evidence to reject null hypothesis.
=> The actual rate is lower. (As
states)
Hope this helps!
:)