Answer:
true
true
false
true
Step-by-step explanation:
47 = 50 - 3 or:
47 = Mean - 1 Standard deviation
For normal distribution it means that 4 bags represent 16 % of all samples.
4 bags ------ 16%
x bags ------ 100 %
---------------------------
4 * 100 = x * 16
16 x = 400
x = 400 : 16
x = 25
Answer: 25 bags were probably taken as samples.
Answer:
It is 20.4 and 16.8
Step-by-step explanation:
This is similar to 8.4 (because its doubled) and it is similar to 10.2 (because its doubled)
Answer:
333 and 1000
Step-by-step explanation:
a]
The expected value of spinning the wheel is given by:
E(x)=2/9(200)+4/9(300)+2/9(400)+1/9(600)
E(x)=44 4/9+133 1/3+88 8/9+66 2/3
E(x)=333 1/3
b] The expected value of spinning the wheel thrice will be:
(expected value of spinning once)*(number of spins)
=333 1/3*3
=1000/3*3
=1000
If you expand out the brackets you get this,
(4+5i)(a+2i) = 4a + (5a)i + 8i - 10
The -10 comes from 5i * 2i.
Squaring i becomes -1.
Let's group the real stuff together,
and imaginary separately,
(4a - 10) + (5a + 8)i
For this to be purely imaginary,
the real part needs to be zero.
Therefore 4a - 10 = 0
Solve for a.
