What is the solution of the equation 4[x + 2(3x – 7)] = 22x

Suppose that 30% of all students who have to buy a text for a particular course want a new copy (the successes!), whereas the ot

ValentinkaMS [17]

Answer:

The probability that all 15 will get the type of book they want from current stock is 0.4838.

Step-by-step explanation:

Denote the random variable X as the number of students who want to buy new copy.

The probability of a student wanting to buy a new copy is, P (X) = p = 0.30.

A random sample of n = 15 students is selected.

The random variable X follows a Binomial distribution.

The probability function of a Binomial distribution is:

$P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0, 1, 2, 3,...$

It is provided that the bookstore has 10 new copies and 10 used copies in stock.

All the 15 students get their desired copy, then this can happen if at most 10 want to buy new copy and at least 5 wants to buy used copy.

Compute the probability of (5 ≤ X ≤ 10) as follows:

P (5 ≤ X ≤ 10) = P (X = 5) + P (X = 6) + P (X = 7) + P (X = 8) + P (X = 9) + P (X = 10)

$={15\choose 5}(0.30)^{5}(1-0.30)^{15-5}+{15\choose 6}(0.30)^{6}(1-0.30)^{15-6}\\+{15\choose 7}(0.30)^{7}(1-0.30)^{15-7}+{15\choose 8}(0.30)^{8}(1-0.30)^{15-8}\\+{15\choose 9}(0.30)^{9}(1-0.30)^{15-9}+{15\choose 10}(0.30)^{10}(1-0.30)^{15-10}\\=0.2061+0.1472+0.0811+0.0348+0.0116+0.0030\\=0.4838$

Thus, the probability that all 15 will get the type of book they want from current stock is 0.4838.

6 0

3 years ago

In 1846 the depth of the river was 2.5 feet deep. In 1847 it rose 9%. This year, 1848, it dropped 6%. How deep is the river now?

Virty [35]

Answer:

So the answer is 2.5615 feet.

Step-by-step explanation:

So the river is 2.5 feet deep, and when you find that 9% is, using the cross-multiplication formula to find the percent then 9% of 2.5 is 0.225, and when you add that to 2.5 you get 2.725, and when you find 6% of 2.725, you get 0.1635, and since it dropped, you subtract, and you end up with 2.5615

Hope I helped

8 0

2 years ago

Please help!!! I’m on functions Khan. Will give Brainliest

SashulF [63]

It’s 20f-30g I just took that question on a test

5 0

3 years ago

Read 2 more answers

Show that tangent is an odd function.Use the figure in your proof.

svlad2 [7]

We have to prove that the tangent is an odd function.

If the tangent is an odd function, the following condition should be satisfied:

$\tan(t)=-\tan(-t)$

From the figure we can see that the tangent can be expressed as:

We can start then from tan(t) and will try to arrive to -tan(-t):

$\begin{gathered} \tan(t)=\frac{\sin(t)}{cos(t)}=\frac{y}{x} \\ \tan(t)=\frac{-(-y)}{x}=\frac{-\sin(-t)}{\cos(-t)} \\ \tan(t)=-\frac{\sin(-t)}{\cos(-t)} \\ \tan(t)=-\tan(-t) \end{gathered}$

We have arrived to the condition for odd functions, so we have just proved that the tangent function is an odd function.

7 0

1 year ago

Express the shaded area as a fraction, a decimal, and a percent of the whole.

ANEK [815]

Answer:

Fraction:7/10 Decimal:0.7 Percent:70%

Step-by-step explanation:

3 0

3 years ago

What is the solution of the equation 4[x + 2(3x – 7)] = 22x – 65?