Answer:
E(x) = 1.43 (Approx)
Step-by-step explanation:
Given:
Total number of camera = 7
Defective camera = 5
Sample selected = 2
Computation:
when x = 0
P(x=0) = 2/7 × 1/6 = 2/42
P(x=1) = [2/7 × 5/6] + [5/7 × 2/6] = 20/42
P(x=2) = 5/7 × 4/6 = 20/42
So,
E(x) = [0×2/42] + [1×20/42] + [2×20/42]
E(x) = 1.43 (Approx)
If they all painted at the same rate the equation is this
mothers 8
daughters 12 at 220 sq ft
mothers 6
daughters 8 at 152 sq ft
220 +152 =372 divided by 34 (because they all painted at the same rate)=10.94 sq ft they each painted
Answer: D
Step-by-step explanation:
You save the most money with option D. Not in the long run though
Answer:
243.01.
Step-by-step explanation:
The first term (a) = 324.
The common ratio (r) = -108/324 = -1/3.
So sum of 9 terms is:
S(9) = 324 * (1 - (-1/3)^9) / ( 1 - (-1/3)
= 324 ( 1 - (-0.00005076)) / 4/3
= 324 * 1.00005076 / 1.33333
= 243.012.
You can know a perfect square trinomial:
i) if the coefficient of a² = 1.
ii) If you divide the middle number coefficient by 2 and you square it you get the last term.
Take for example the first option:
For all the options, the coefficient of a² = 1
a² + 4a + 16.
Coefficient of a = 4.
4/2 = 2
2² = 4, this does not equal the last term so it is not a perfect square trinomial.
a² + 14a + 49.
Coefficient of a = 14.
14/2 = 7
7² = 49, this is equal the last term so it is a perfect square trinomial.
And the perfect square is (a +7)²
Similarly if you test the last option.
a² + 26a + 169.
Coefficient of a = 26.
26/2 = 13
13² = 169, this is equal the last term so it is a perfect square trinomial.
And the perfect square is (a +13)²
So the only two options are: a² + 14a + 49 and a² + 26a + 169.
Other options do not pass this test.
