11: B
12: C
They are both supplementary angles meaning they add to 180 degrees
Answer:
idk
Step-by-step explanation:
What you do you have to find someone more smarter than me!
Download photo math and it will let you take a picture of the equation and answer it for you
Answer: 0.0228
Step-by-step explanation:
Given : The mean and the standard deviation of finish times (in minutes) for this event are respectively as :-

If the distribution of finish times is approximately bell-shaped and symmetric, then it must be normally distributed.
Let X be the random variable that represents the finish times for this event.
z score : 

Now, the probability of runners who finish in under 19 minutes by using standard normal distribution table :-

Hence, the approximate proportion of runners who finish in under 19 minutes = 0.0228
Answer:
Yes, this is a valid inference because she took a random sample of the neighborhood.
Step-by-step explanation:
As her survey was non bias and completely random and she found that 15% of the families would participate in the event. She claims that 15% of the neighborhood families would be expected to participate in the sports event. So, yes, this is a valid inference because she took a random sample of the neighborhood.