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.
The distance from the center to where the foci are located exists 8 units.
<h3>How to determine the distance from the center?</h3>
The formula associated with the focus of an ellipse exists given as;
c² = a² − b²
Where c exists the distance from the focus to the center.
a exists the distance from the center to a vertex,
the major axis exists 10 units.
b exists the distance from the center to a co-vertex, the minor axis exists 6 units
c² = a² − b²
c² = 10² - 6²
c² = 100 - 36
c² = 64

c = 8
Therefore, the distance from the center to where the foci are located exists 8 units.
To learn more about the Pythagorean theorem here:
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Answer:
ASA test will come
angles (given)
side between angles (common side)
Answer:
see explanation
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Subtract the sum of the given angles from 180 for A
A = 180° - (90 + 46)° = 180° - 136° = 44°
----------------------------------------------------------------
tan46° =
= 
Multiply both sides by 23
23 × tan46° = b, thus
b ≈ 23.8 ( to the nearest tenth )
-----------------------------------------------------------------
cos46° =
= 
Multiply both sides by c
c × cos46° = 23 ( divide both sides by cos46° )
c =
≈ 33.1 ( to the nearest tenth )
The number of defective modems in the inventory is 20%⋅ 30 + 8%⋅ 50 = 10 (out of 80).
Note that the number of defectives in the inventory is fixed, i.e., we are not told that there
is 1
8 probability that a modem in the inventory is defective, but rather that exactly 1
8
of
all modems are defective. The probability that exactly two modems in a random sample
of five are defective is = 0.102