Answer: b. 0.8413
Step-by-step explanation:
Given : The average time taken to complete an exam, X, follows a normal probability distribution with
and
.
Then, the probability that a randomly chosen student will take more than 30 minutes to complete the exam will be :-
[using z-value table]
Hence, the probability that a randomly chosen student will take more than 30 minutes to complete the exam = 0.8413
Ok, so if the angle is 120 degrees, its one third of the full cake (which is 360 degrees). So the area of the whole circle (worked out with area = pi * r^2 where r is 30) gives 900*pi, and so one third of that (because her slice is one third) is 300pi.
Answer:
a) 0.954
b) 0.937
c) 0.891
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 6 percent
Standard Deviation, σ = 1.3 percent
We are given that the distribution of particular interest rate is a bell shaped distribution that is a normal distribution.
Formula:
a) P(At least 3.8 percent.)
Calculation the value from standard normal z table, we have,
b) P(At most 8 percent)
Calculating the value from the standard normal table we have,
c) P(Between 3.8 percent and 8 percent. )

Lets split the box in pieces and then add:
top = 20*15 = 300
sidesA = 2*20*9 = 360, is multiplied by 2 cause there are 2 sides like this
sidesB = 2*9*15 = 270, is multiplied by 2 cause there are 2 sides like this
so in total we have:
total = 300 + 360 + 270 = 930 cm^2
if we express this quantity in mm^2 we have:
<span>1cm² = 100 mm²</span>total = 930*100 = 93000 mm^2
so if the tiles are 5 mm^2 we need:
total tiles = <span>93000/5 = 18600
we need 18600 tiles of 5 mm^2</span>