Question

As a binomial question: Flip a coin twice. The probability of observing a head is 50%, what is the probability that I observe 1 head? binompdf (n, p, x) so binompdf( 2, .50,1) Sampling Proportion question (8.2): There is a 50% of observing a head. If we flip the coin 100 times, what is that at most 30% of the flips will be heads? n*p*(1-p) =100*.50*.50=25 (Do not use my coin example. Use your own scenario). pˆ=.30 po or μ=50 Image result for sample proportion z formula NormalCDF (-999,.30,.50,.05) raw numbers z=.30−.50.50(1−.50)100√=−.20.05=−4 NormalCDF(-999,-4) standardized that means the mean is 0 and standard deviation is 1.

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Answer 1

As a binomial question: Flip a coin twice. The probability of observing a head is 50%, what is the probability that I observe 1 head? binompdf (n, p, x) so binompdf( 2, .50,1)

Here X = number of heads. So X takes three values as 0, 1, 2

So that n = 2, p = 0.5, x = 1

Let's use TI-84 Plus calculator:

Click on 2ND >>> VARS >>>DISTR >>> A: binompdf( >>> ENTER

trials : 2

p: 0.5

x value : 1

Paste.

So we get the following output:

0.5

So answer is 0.5

Let X = number of boys in two births

So X takes the values as 0, 1 , 2

Similarly, we want to find the probability of proportion of boys is at most 0.3 in the 100 new birth.

So you can use above command to find this type of example;

Note that : Here we assume that the the chance of gender as girl or boys of a new born baby is same as 0.5.