Answer:
23.8 i think
Step-by-step explanation:
Answer: 208.
Step-by-step explanation:
The formula to find the minimum sample size is given by :-
(1)
, where z* = critical z-value (two tailed).
= Standard deviation ( from prior study ) and E = Margin of error.
As per given , we have
Margin of error : E= 0.29
Confidence level = 85%
Significance level =![\alpha=1-0.85=0.15](https://tex.z-dn.net/?f=%5Calpha%3D1-0.85%3D0.15)
Using z-table , the critical value (two -tailed)=![z^*=z_{\alpha/2}=z_{0.15/2}=z_{0.075}=1.439](https://tex.z-dn.net/?f=z%5E%2A%3Dz_%7B%5Calpha%2F2%7D%3Dz_%7B0.15%2F2%7D%3Dz_%7B0.075%7D%3D1.439)
As per previous study , Variance =![\sigma^2=8.41](https://tex.z-dn.net/?f=%5Csigma%5E2%3D8.41)
![\sigma=\sqrt{8.41}=2.9](https://tex.z-dn.net/?f=%5Csigma%3D%5Csqrt%7B8.41%7D%3D2.9)
Now, the required minimum sample size =
[Substitute the values in formula (1)]
![n=(14.39)^2](https://tex.z-dn.net/?f=n%3D%2814.39%29%5E2)
[ Round to the next integer]
Hence, the minimum number of third graders that must be included in a sample = 208.
Answer:
![P(n>55)=0.1357](https://tex.z-dn.net/?f=P%28n%3E55%29%3D0.1357)
Step-by-step explanation:
From the question we are told that:
Sample size n=100
Sample space n'=36
Generally the equation for the mean number of times odds appears is mathematically given by
![\=x_o=hp](https://tex.z-dn.net/?f=%5C%3Dx_o%3Dhp)
![\=x_o=100*0.5](https://tex.z-dn.net/?f=%5C%3Dx_o%3D100%2A0.5)
![\=x_o=50](https://tex.z-dn.net/?f=%5C%3Dx_o%3D50)
Generally the equation for standard deviation is mathematically given by
![\sigma=(hp(1-p))^{1/2}\\\sigma=(50(0.5))^{1/2}](https://tex.z-dn.net/?f=%5Csigma%3D%28hp%281-p%29%29%5E%7B1%2F2%7D%5C%5C%5Csigma%3D%2850%280.5%29%29%5E%7B1%2F2%7D)
![\sigma=5](https://tex.z-dn.net/?f=%5Csigma%3D5)
Therefore probability to make wrong decision P(n>55)
![P(n>55)=1-P(z55)=1-P(z55)=1-0.86](https://tex.z-dn.net/?f=P%28n%3E55%29%3D1-P%28z%3C50.5%2F5%29%5C%5CP%28n%3E55%29%3D1-P%28z%3C1.1%29%5C%5CP%28n%3E55%29%3D1-0.86)
![P(n>55)=0.1357](https://tex.z-dn.net/?f=P%28n%3E55%29%3D0.1357)