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Nimfa-mama [501]
1 year ago
11

recent research indicated that about 20% of british children are deficient in vitamin d. suppose doctors test a group of element

ary school children. a) what's the probability that the first vitamin d-deficient child is the 8th one tested?
Mathematics
1 answer:
blsea [12.9K]1 year ago
8 0

If about 20% of British children are deficient in vitamin and doctors test a group of elementary school children, the probability that the first vitamin d-deficient child is the 8th one tested is 4.19% determined using geometric distribution formula.

In probability and statistics, geometric distribution refers to the probability that first success would occurs after n number of trials and is given by:

P(X)=q^(x-1)p

Where p is the probability of success and q is (1-p)

In this case,

p=probability of children deficient in vitamin= 0.2

q= probability of children not deficient in vitamin= 0.8

Hence,

P(8)=0.8^(8-1)*0.2= 0.0419

Hence, the probability that 8th child is deficient is 4.19%

Learn more about geometric distribution:

brainly.com/question/14957440

#SPJ4

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At the bank, Sheila made 6 deposits, each in the same amount. Her sister Sherri made 5 deposits, each in the same amount. Each o
Serga [27]
<span /><span>TLDR: Equation is 5(10 + x) = 6x. x = 50, so Sheila deposited $50 each 6 trips. Sherri deposited $60 each 5 trips. Both of them deposited $300 in total.

</span>Sherri deposited $10 more into her bank account than Sheila each 5 times. Expression: 5(x + 10).

Sheila deposited money 6 times
Expression: (6)(x) or 6x

Put it all together and the equation is 5(x+10)=6x. 

Solve by distributing the 5 on the right side of the equation 5(x+10) to get 5x + 50 = 6x. Subtract 5x on both sides of equation. 5x - 5x + 50 = 6x - 5x to get 50 = 1x. Divide by 1 on each side to isolate the variable. x = 50. Sheila paid $50 in each of her 6 deposits, so she deposited $300 in total. Check the equation by replacing x with 50. 

Sherri paid $60 in each of her 5 deposits because 50 + 10 is 60. 60 by 5 is also $300. 


3 0
3 years ago
The sum of two-sevenths of a number and 3 is 9. Can you please write out into an equation&gt;~
serg [7]

Answer:

2/7x +3=9

x=21

Step-by-step explanation:

Let the unknown be x.

Take 3 to the other side so: 2/7 multiplied by x= 6

Divide 6 by 2/7 to get the answer;

Therefore x=21

Sub back into equation to check answer.

4 0
3 years ago
Read 2 more answers
Which of the following statements are not true in developing a confidence interval for the population mean?
frutty [35]

Answer:

b) The width of the confidence interval becomes narrower when the sample mean increases.

Step-by-step explanation:

The confidence interval can be calculated as:

\bar{x} \pm \text{Test Statistic}\displaystyle\frac{\sigma}{\sqrt{n}}

a) The width of the confidence interval becomes wider as the confidence level increases.

The above statement is true as the confidence level increases the width increases as the absolute value of test statistic increases.

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The above statement is false. As the sample mean increases the width of the confidence interval increases.

c) The width of the confidence interval becomes narrower when the sample size n increases.

The above statement is true as the sample size increases the standard error decreases and the confidence interval become narrower.

8 0
3 years ago
Help me please it hardddd
iogann1982 [59]

There are a total 40 cars

and there is x yellow cars

and there are nine times as much white cars (9x white cars) lol

so x+9x=40

simplify 10x=40

divide both sides by ten 10x/10=40/10

x=4

we are looking for the number of WHITE cars sooo we multiply by 9-

9x=36

how is this "hardddd" no offence*

sorry im a mean person


3 0
3 years ago
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=\frac{3π+8}{64}

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