Answer:
<h2><u><em>
n = 8</em></u></h2>
Step-by-step explanation:
2n + 1.6 = 17.6 what is the value of n?
2n + 1.6 = 17.6
2n = 17.6 - 1.6
2n = 16
n = 16 : 2
n = 8
-----------------
check
2n + 1.6 = 17.6
2*8+1.6=17.6
16+1.6=17.6
17.6=17.6
the answer is good
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
A complex fraction is. Fraction at a whole number