Answer:
Probability = 0.15%
Step-by-step explanation:
The provided information is:
Let X be the scores of the IQ scores that is normally distributed with mean
and standard deviation
.
That is ![X \sim N(103,15)](https://tex.z-dn.net/?f=X%20%5Csim%20N%28103%2C15%29)
![103 - 58 = 45 = 3 \times 15](https://tex.z-dn.net/?f=103%20-%2058%20%3D%2045%20%3D%203%20%5Ctimes%2015)
So, 58 is 3 standard deviation left to the mean.
As 99.7% of probability lies within the three standard deviation.
Thus, above three standard deviation is:
![\frac{1-0.997}{2}=0.0015](https://tex.z-dn.net/?f=%5Cfrac%7B1-0.997%7D%7B2%7D%3D0.0015)
Thus, the required probability is 0.15%
The probability that the teacher will choose a boy at random the first time is 7/10. After the first boy is picked, that leaves 9 people remaining, 3 girls and 6 boys, giving us a chance that a boy will be picked 6/9, or 2/3 of the time. We can multiply these fractions to give us the final chance two boys will be picked. 7/10 x 2/3 = 7/15 in simplest form. The teacher will choose two boys 7/15 of the time.
A would be the Answer because it is in standard form
It means t is less than or equal to -4 so it could be -4 or below. Any other questions? :)