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!
:)