H=henry's age
j=julia's age
r=rhianna's age
h is 3 times of j
h=3j
r is 1/2 times of j
r=(1/2)j or
2r=j
so
h=3j
2r=j
sub 2r for j
h=3(2r)
h=6r
henry's age is 6 times of rhianna's age
An irrational number is one that can’t be expressed as a simple fraction.
For instance, the first few digits of the square root of two is written as 1.414213562373095... The digits keep going and cannot be expressed as a fraction. But think of 0.33333... That can easily be written as one-third. The distinguishing feature is that there’s no pattern in the digits for the square root of two.
The first two options are integer fractions. We rule those out immediately. The square root of four is tempting, but realize that it is just equal to two. We come to π (pi).
Arguably the most famous irrational number is π, which starts off as 3.14159265358979... Here, there is again no pattern and the digits extend forever. This meets our definition of our irrational.
Answer:
<u>Explanation</u>:
<u>Given:</u>
<u>using this formula:</u>
We have been given for a normal distribution the mean time it takes to walk to the bus stop is 8 minutes with a standard deviation of 2 minutes. And the mean time it takes for the bus to get to school is 20 minutes with a standard deviation of 4 minutes.
(a) Average time that it would take reach school can be obtained by adding the average times.
8+20 = 28 minutes.
(b) Standard deviation of the trip to school can be found as:
Therefore, standard deviation of the entire trip is 4.47 minutes.
(c) Let us first find z score corresponding to 30 minutes.
We need to find the probability such that
Therefore, the required probability is 0.67.
(d) If average time to walk to school is 10 minutes, then overall average time for the trip will be 10+20 = 30 minutes.
(e) Standard deviation won't change it will remain 4.47
(f) The new probability will be:
Therefore, probability will be 0.50.