Answer: 0.16
Step-by-step explanation:
Given that the run times provided are normally distributed ;
Mean(x) of distribution = 3 hours 50 minutes
Standard deviation(s) = 30 minutes
The probability that a randomly selected runner has a time less than or equal to 3 hours 20 minutes
3 hours 20 minutes = (3 hrs 50 mins - 30 mins):
This is equivalent to :
[mean(x) - 1 standard deviation]
z 1 standard deviation within the mean = 0.84
z, 1 standard deviation outside the mean equals:
P(1 - z value , 1standard deviation within the mean)
1 - 0.8413 = 0.1587
= 0.16
We are given with a limit and we need to find it's value so let's start !!!!
But , before starting , let's recall an identity which is the <em>main key</em> to answer this question
Consider The limit ;
Now as directly putting the limit will lead to <em>indeterminate form 0/0.</em> So , <em>Rationalizing</em> the <em>numerator</em> i.e multiplying both numerator and denominator by the <em>conjugate of numerator </em>

Using the above algebraic identity ;


Now , here we <em>need</em> to <em>eliminate (√x-2)</em> from the denominator somehow , or the limit will again be <em>indeterminate </em>,so if you think <em>carefully</em> as <em>I thought</em> after <em>seeing the question</em> i.e what if we <em>add 4 and subtract 4</em> in <em>numerator</em> ? So let's try !


Now , using the same above identity ;


Now , take minus sign common in <em>numerator</em> from 2nd term , so that we can <em>take (√x-2) common</em> from both terms

Now , take<em> (√x-2) common</em> in numerator ;

Cancelling the <em>radical</em> that makes our <em>limit again and again</em> <em>indeterminate</em> ;

Now , <em>putting the limit ;</em>

Answer:
Option A is correct.
Step-by-step explanation:
64 < x < 68
This inequality represent that the height x should be greater than 64 and less than 68.i.e.
x>64 and x<68
So, Option A is correct.
X's cancel 5y = 20 y= 4 X=0
Answer:
37 hours
Step-by-step explanation:
4.5 + 8.75 + 9.5 + 10 + 4.25 = 37 hours