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!
:)
Answer:
4
Step-by-step explanation:
Let's say B is the number of boys and T is the number of teachers.
T / (B + 18) = 2/21
B/18 = 4/3
Solve the second equation for B.
B = 24
Plug into the first equation to find T.
T / (24 + 18) = 2/21
T = 4
Just a regular pentagon has 5 sides. and also has 5 lines of symmetry.
So if a shape has 7 sides it will have 7 lines of symmetry.
Its always going to be the same number.
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