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2 years ago

The variance Var(x) for the binomial distribution is given by equation :

Mathematics

1 answer:

aliina [53]2 years ago

6 0

Answer: d. np(1 - p).

Step-by-step explanation:

Let x be any binomial variable which represents the number of success such that $X\sim B(n, p)$ , where n is the sample size or the total number of trials and p is the probability of getting success in each trial .

Then, the mean E(x) and the variance Var(x) for the binomial distribution is given by equation :

$E(x)=\mu=np$

$Var (x)=\sigma^2=np(1-p)$

where n is the sample size or the total number of trials and p is the probability of getting success in each trial .

Therefore , the correct option is option d. np(1 - p) .

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If a linear system has four equations and seven variables, then it must have infinitely many solutions. True or False

Savatey [412]

Answer:

The statement is False.

Step-by-step explanation:

Consider the provided information.

If a linear system has four equations and seven variables, then it must have infinitely many solutions.

We need to determine the above statement is true or false.

The above statement is false, it could be inconsistent, and therefore have no solutions,

For example:

$x_1+x_2+x_3+x_4 +x_5+x_6+x_7=0\\x_1+x_2+x_3 =1\\x_4 +x_5 =1\\x_6+ x_7=1$

Hence, there is no solution.

7 0

2 years ago

Peter has 96 stamps and Sam has 63. How many stamps should Sam give Peter so that Peter will have twice as many stamps as Sam?

MAXImum [283]

96÷2=48
63-48=15

So Sam should give Peter 15 of his stamps so that Peter will have twice as many stamps as him.

4 0

2 years ago

Read 2 more answers

The percent defective for parts produced by a manufacturing process is targeted at 4%. The process is monitored daily by taking

Anna [14]

Answer:

The 88% confidence interval for the proportion of defectives today is (0.053, 0.123)

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 160, \pi = \frac{14}{160} = 0.088$

88% confidence level

So $\alpha = 0.12$ , z is the value of Z that has a pvalue of $1 - \frac{0.12}{2} = 0.94$ , so $Z = 1.555$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.088 - 1.555\sqrt{\frac{0.088*0.912}{160}} = 0.053$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.088 + 1.555\sqrt{\frac{0.088*0.912}{160}} = 0.123$

The 88% confidence interval for the proportion of defectives today is (0.053, 0.123)

6 0

2 years ago

Part of a book fell out. The first page of this part has number 143. The last page has a number written with the same digits. Ho

Gnom [1K]

Answer:

142 pages

Step-by-step explanation:

The parameters given are

First page of part of the book available = 143

The last is numbered with the digits 143

Since the book is said to have been split into two parts with, we have that one part of the book starts from the beginning, while the other part continue from the first part stops

Number on the pages on the first part = from 1 to number on the first page on the second part - 1

Hence, the part of the book available is the second part and the number of pages in the first part = 1 to 142 or 142 pages.

3 0

2 years ago

If 2^2008 – 2^2007 - 2^2006 + 2^2005 = k * 2^2005 then the value of k is equal to

scZoUnD [109]

Step-by-step explanation:

Maths

Bookmark

if 2

2008

−2

2007

−2

2006

2005

=k ⋅2

2005

then the value of k is equal to

Answer

Correct option is

2008

−2

2007

−2

2006

2005

=k⋅2

2005

⇒[2

2008

−2

2006

]−[2

2007

−2

2005

]=k⋅2

2005

⇒2

2006

−1)−2

2005

−1)=k⋅2

2005

⇒3(2

2006

−2

2005

)=k⋅2

2005

⇒3[2

2005

(2−1)]=k⋅2

2005

⇒3(2

2005

)=k⋅2

2005

On comparing, we get

k=3

Hence, Option B is correct.

5 0

1 year ago

Read 2 more answers