Answer:
0.2755
Step-by-step explanation:
We intend to make use of the normal approximation to the binomial distribution.
First we'll check to see if that approximation is applicable.
For p=10% and sample size n = 500, we have ...
pn = 0.10(500) = 50
This value is greater than 5, so the approximation is valid.
__
The mean of the distribution we'll use as a model is ...
µ = p·n = 0.10(500)
µ = 50
The standard deviation for our model is ...
σ = √((1-p)µ) = √(0.9·50) = √45
σ ≈ 6.708204
__
A continuity correction can be applied to better approximate the binomial distribution. We want p(t ≤ 9.1%) = p(t ≤ 45.5). For our lookup, we will add 0.5 to this limit, and find p(t ≤ 46).
The attached calculator shows the probability of fewer than 45.5 t's in the sample is about 0.2755.
If your surveys are the following:
A. A survey of 110 teachers showed that 28 of them have a second job.
<span>B. A survey of 90 teachers showed that 27 of them have a second job. </span>
<span>C. A survey of 70 teachers showed that 21 of them have a second job. </span>
<span>D. A survey of 80 teachers showed that 32 of them have a second job.
</span>
Then the answer is B and C
Answer:
D
Step-by-step explanation:
You just need to calculate it as usual. Might as well do in fraction form for clearer understandings
X-2=27
is this a good equations