Answer:
<em>The answers are for option (a) 0.2070 (b)0.3798 (c) 0.3938
</em>
Step-by-step explanation:
<em>Given:</em>
<em>Here Section 1 students = 20
</em>
<em>
Section 2 students = 30
</em>
<em>
Here there are 15 graded exam papers.
</em>
<em>
(a )Here Pr(10 are from second section) = ²⁰C₅ * ³⁰C₁₀/⁵⁰C₁₅= 0.2070
</em>
<em>
(b) Here if x is the number of students copies of section 2 out of 15 exam papers.
</em>
<em> here the distribution is hyper-geometric one, where N = 50, K = 30 ; n = 15
</em>
<em>Then,
</em>
<em>
Pr( x ≥ 10 ; 15; 30 ; 50) = 0.3798
</em>
<em>
(c) Here we have to find that at least 10 are from the same section that means if x ≥ 10 (at least 10 from section B) or x ≤ 5 (at least 10 from section 1)
</em>
<em>
so,
</em>
<em>
Pr(at least 10 of these are from the same section) = Pr(x ≤ 5 or x ≥ 10 ; 15 ; 30 ; 50) = Pr(x ≤ 5 ; 15 ; 30 ; 50) + Pr(x ≥ 10 ; 15 ; 30 ; 50) = 0.0140 + 0.3798 = 0.3938
</em>
<em>
Note : Here the given distribution is Hyper-geometric distribution
</em>
<em>
where f(x) = kCₓ)(N-K)C(n-x)/ NCK in that way all these above values can be calculated.</em>
<u>Answer:
</u>
Physliis invested 32000 dollar at 5% interest rate and 34000 dollar at 7% interest rate.
<u>Solution:</u>
Let Phyllis invest ‘x’ dollar at 5% per year and (66000-x) dollar at 7% per year.
We know,

In the question it is given that Simple interest earned from both the investments at the end of the year is $3980.
Using the given below equation, we will try to find out the investments at each rate.

x = 32000
We can calculate amount for 7% interest rate by,
(66000-32000) =34000
Thus Phyllis invested 32000 dollar at 5% interest rate and 34000 dollar at 7% interest rate.
Answer: 8 gallons of water.
Step-by-step explanation:
3 x 4 x 5 = 60.
60 divided by the number of gallons per cubic foot 7.5 = 8 gallons. :)
Im so sorry but i am not into that:(
<span>commutative property of addition (changing order of numbers)
</span>
Answer:
2 + (3 + 4) = (2 + 3) + 4