Answer:
12
Step-by-step explanation:
25%=1/4
of=*
3=1/4x
3 divided by 1/4 or 0.25 =12
Answer:
The mean score is 87
Step-by-step explanation:
79x2=158
158-71=87
Answer:
2.8
Step-by-step explanation:
I hope this helps!
what is the best and easiest method to use to find sides A and B?
B
Answer: 0.6812
Step-by-step explanation:
Let p be the population proportion of trees are infested by a bark beetle.
As per given: p= 12%= 0.12
Sample size : n= 1000
Number of trees affected in sample = 1000
Sample proportion of trees are infested by a bark beetle. = ![\hat{p}=\dfrac{127}{1000}=0.127](https://tex.z-dn.net/?f=%5Chat%7Bp%7D%3D%5Cdfrac%7B127%7D%7B1000%7D%3D0.127)
Now, the z-test statistic : ![z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7B%5Chat%7Bp%7D-p%7D%7B%5Csqrt%7B%5Cdfrac%7Bp%281-p%29%7D%7Bn%7D%7D%7D)
So, ![z=\dfrac{0.127-0.12}{\sqrt{\dfrac{0.12\times 0.88}{1000}}}](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7B0.127-0.12%7D%7B%5Csqrt%7B%5Cdfrac%7B0.12%5Ctimes%200.88%7D%7B1000%7D%7D%7D)
![z=\dfrac{0.007}{\sqrt{\dfrac{0.1056}{1000}}}\\\\\\=\dfrac{0.007}{\sqrt{0.0001056}}\\\\\\=\dfrac{0.007}{0.010276}\approx0.6812](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7B0.007%7D%7B%5Csqrt%7B%5Cdfrac%7B0.1056%7D%7B1000%7D%7D%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B0.007%7D%7B%5Csqrt%7B0.0001056%7D%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B0.007%7D%7B0.010276%7D%5Capprox0.6812)
Hence, the value of the z-test statistic = 0.6812 .