Answer:
7.5 * 10^-4
Step-by-step explanation:
To express this, we will have to multiply 750 by the conversion unit
we have this as;
750 * 10^-6
750 = 7.5 * 10^2
so we have;
7.5 * 10^2 * 10^-6
= 7.5 * 10^(-6+2)
= 7.5 * 10^-4
Answer:
a) 390
b)108
I hope this answer was helpfull for you
Answer:
11 boys walk to school each day
Step-by-step explanation:
<em>*The following will be assumed: the only genders of students in the class are male or female; the only options for getting to school are walking or not walking</em>
If there are 32 students in the class total, and there are 15 boys,
32 - 15 = 17
there are 17 girls.
If 8 of these girls do not walk to school,
17 - 8 = 9
9 girls walk to school
So, if 20 total students walk to school, and 9 of those are girls
20 - 9 = 11
11 boys walk to school each day.
Answer:
a) the probability that the minimum of the three is between 75 and 90 is 0.00072
b) the probability that the second smallest of the three is between 75 and 90 is 0.396
Step-by-step explanation:
Given that;
fx(x) = { 1/5 ; 50 < x < 100
0, otherwise}
Fx(x) = { x-50 / 50 ; 50 < x < 100
1 ; x > 100
a)
n = 3
F(1) (x) = nf(x) ( 1-F(x)^n-1
= 3 × 1/50 ( 1 - ((x-50)/50)²
= 3/50 (( 100 - x)/50)²
=3/50³ ( 100 - x)²
Therefore P ( 75 < (x) < 90) = ⁹⁰∫₇₅ 3/50³ ( 100 - x)² dx
= 3/50³ [ -2 (100 - x ]₇₅⁹⁰
= (3 ( -20 + 50)) / 50₃
= 9 / 12500 = 0.00072
b)
f(k) (x) = nf(x) ( ⁿ⁻¹_k₋ ₁) ( F(x) )^k-1 ; ( 1 - F(x) )^n-k
Now for n = 3, k = 2
f(2) (x) = 3f(x) × 2 × (x-50 / 50) ( 1 - (x-50 / 50))
= 6 × 1/50 × ( x-50 / 50) ( 100-x / 50)
= 6/50³ ( 150x - x² - 5000 )
therefore
P( 75 < x2 < 90 ) = 6/50³ ⁹⁰∫₇₅ ( 150x - x² - 5000 ) dx
= 99 / 250 = 0.396
