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3 years ago

A person flipped a coin 100 times and obtained 73 heads. Can the person conclude that the coin was unbalanced?

Mathematics

2 answers:

Kitty [74]3 years ago

8 0

They can not, there are only 2 sides and they probably flipped it different ways. They got 'lucky'.

Taya2010 [7]3 years ago

8 0

No, a coin has ONLY TWO sides...meaning it CANT be unbalanced. If it somehow landed on its side then it would have gotten heads.

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Which ordered pair is not a solution of the equation y = 2x – 1

TEA [102]

Answer:

Step-by-step explanation:

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3 years ago

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7/12 fractions that is equivalent to 2/4

zhenek [66]

Answer:

Step-by-step explanation:

So we multiply 7 by 4, and get 28. Then we multiply 2 by 12, and get 24. Next we give both terms new denominators 12 × 4 = 48.

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3 years ago

A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained i

Scorpion4ik [409]

Answer:

a) We need a sample size of at least 3109.

b) We need a sample size of at least 4145.

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 $1 - \frac{\alpha}{2}$ .

The margin of error is:

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

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

(a) he uses a previous estimate of 25%?

we need a sample of size at least n.

n is found when $M = 0.02, \pi = 0.25$ . So

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

$0.02 = 2.575\sqrt{\frac{0.25*0.75}{n}}$

$0.02\sqrt{n} = 2.575\sqrt{0.25*0.75}$

$\sqrt{n} = \frac{2.575\sqrt{0.25*0.75}}{0.02}$

$(\sqrt{n})^{2} = (\frac{2.575\sqrt{0.25*0.75}}{0.02})^{2}$

$n = 3108.1$

We need a sample size of at least 3109.

(b) he does not use any prior estimates?

When we do not use any prior estimate, we use $\pi = 0.5$

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

$0.02 = 2.575\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 2.575\sqrt{0.5*0.5}$

$\sqrt{n} = \frac{2.575\sqrt{0.5*0.5}}{0.02}$

$(\sqrt{n})^{2} = (\frac{2.575\sqrt{0.5*0.5}}{0.02})^{2}$

$n = 4144.1$

Rounding up

We need a sample size of at least 4145.

8 0

3 years ago

Help me with this very confused

NNADVOKAT [17]

Answer:

$\frac{3 - 5x}{2}$

Step-by-step explanation:

Set g(x)=y

y=-2/5x+3

5y=-2x+3

2x=3-5y

x=3-5y/2

So g^-1(x)=

$\frac{3 - 5x}{2}$

6 0

2 years ago

A/b=2/5 and b/c=3/8 find a/c

m_a_m_a [10]

Answer:

$\frac{a}{c}$ = $\frac{3}{20}$

Step-by-step explanation:

$\frac{a}{c}$ = $\frac{a}{b}$ × $\frac{b}{c}$ = $\frac{2}{5}$ × $\frac{3}{8}$ = $\frac{6}{40}$ = $\frac{3}{20}$

3 0

2 years ago