Since the sixth term is 1215 and the 5th term is 405, we know each term is 3 times more than the last.
Let 'n' represent the first term, then the sum of the first 9 terms can be written as:
n+3n+9n+27n+81n+243n+729n+2187n+6561n
which sinplifies to 9841n
since each term is 3 times the last, the first term must be 405 divided by 3, 4 times in total, which is 5
Now subsitute 'n' for 5, and we get 9841(5)
which is 49205 which is the answer.
Hope this helps
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
600 divided by 20=30
30x2=60 which is the answer
equation= 600=2x area divied by height
Answer:

Step-by-step explanation:
When solving for 1 variable, set the other to 0 and solve.

Answer:
Intersection point of this is (0,-0.5)
Step-by-step explanation:
Hope this helps :)