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# Binomial hypothesis testing question s2

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1. I have been given a hypothesis testing question to do but with no situation or context.
Null Hypothesis: p=0.25
Alternate Hypothesis: p>0.25
N=10
x=5.
sig level: 5%

can someone explain why I would need to find p(x is greater or equal to 5) please.
2. (Original post by kevvvvvv)
I have been given a hypothesis testing question to do but with no situation or context.
Null Hypothesis: p=0.25
Alternate Hypothesis: p>0.25
N=10
x=5.
sig level: 5%

can someone explain why I would need to find p(x is greater or equal to 5) please.
The null hypothesis is rejected if P(X >= x) <= 5% (since the alternate hypothesis is p > 0.25, if it was p < 0.25, you'd do P(X<= x))

In this case, x = 5. So P (X >= 5) - then use binomial tables with P (X >= 5) = 1 - P(X <= 4).
X ~ B(10, p)

Sorr for lack of LaTeX I'm not home and typing on my phone is shite
3. (Original post by Zacken)
The null hypothesis is rejected if P(X >= x) <= 5% (since the alternate hypothesis is p > 0.25, if it was p < 0.25, you'd do P(X<= x))

In this case, x = 5. So P (X >= 5) - then use binomial tables with P (X >= 5) = 1 - P(X <= 4).
X ~ B(10, p)

Sorr for lack of LaTeX I'm not home and typing on my phone is shite
no worries that makes sense thank you
4. (Original post by kevvvvvv)
no worries that makes sense thank you
Yay, no problem!
5. (Original post by Zacken)
...
I've had this problem doing S2 hypothesis testing. While testing a discrete distribution, I usually draw a normal curve just to make things easier to understand. For example, if they're asking to find the critical values of X ~ B(30, 0.25), I'll draw a normal curve with the mean = np just for reference. Our school teacher taught us this method, but I'm worried that the examiner will assume that I don't know the difference between a discrete and a continuous distribution. Would this affect the way they mark it, you think (assuming my working is all correct)?
6. (Original post by aymanzayedmannan)
I've had this problem doing S2 hypothesis testing. While testing a discrete distribution, I usually draw a normal curve just to make things easier to understand. For example, if they're asking to find the critical values of X ~ B(30, 0.25), I'll draw a normal curve with the mean = np just for reference. Our school teacher taught us this method, but I'm worried that the examiner will assume that I don't know the difference between a discrete and a continuous distribution. Would this affect the way they mark it, you think (assuming my working is all correct)?
Nah, definitely not. You might want to scratch a line through it once you're done with the question for your own peace of mind, though.
7. (Original post by kevvvvvv)
I have been given a hypothesis testing question to do but with no situation or context.
Null Hypothesis: p=0.25
Alternate Hypothesis: p>0.25
N=10
x=5.
sig level: 5%

can someone explain why I would need to find p(x is greater or equal to 5) please.
If the alternative hypothesis had been p not = 0.25, you would have to compare the mean np with the x value. np = 10 x 0.25 = 2.5 x = 5 is bigger than the mean, so you would still have looked at P(X>=5) since you want a small probability to compare with half of 5%.
8. it is a single tailed test so use all of the 5% in the comparison stage.
9. (Original post by kevvvvvv)
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