How many solutions can be found for the equation 5x + 3(x − 1) = 10x − 2x − 3? (4 points) None

A doctor at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she

Nataly_w [17]

Answer:

The minimum sample size needed is $n = (\frac{1.96\sqrt{\sigma}}{4})^2$ . If n is a decimal number, it is rounded up to the next integer. $\sigma$ is the standard deviation of the population.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?

A sample of n is needed, and n is found when M = 4. So

$M = z\frac{\sigma}{\sqrt{n}}$

$4 = 1.96\frac{\sigma}{\sqrt{n}}$

$4\sqrt{n} = 1.96\sqrt{\sigma}$

$\sqrt{n} = \frac{1.96\sqrt{\sigma}}{4}$

$(\sqrt{n})^2 = (\frac{1.96\sqrt{\sigma}}{4})^2$

$n = (\frac{1.96\sqrt{\sigma}}{4})^2$

The minimum sample size needed is $n = (\frac{1.96\sqrt{\sigma}}{4})^2$ . If n is a decimal number, it is rounded up to the next integer. $\sigma$ is the standard deviation of the population.

4 0

3 years ago

Enid's and petter's cars weigh a total of 2.1 tonnes. Edins car weighs 280 kg more than Peter's car

kupik [55]

Answer:

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Step-by-step explanation:

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8 0

3 years ago

When solving the equation 4(3x+2)-9=8x+7, Emily wrote 4(3x+2)=8x+16 as her first step. Which property justifies Emily's first st

nataly862011 [7]

The Addition Property of Equality justifies Emily's first step. She added 9 to both sides, canceling out the minus 9 while keeping the equation equal.

6 0

3 years ago

Please, help im being timed !!!

Agata [3.3K]

B (2x+5y=-10) is the answer.

3 0

3 years ago

Combine the radicals -2 Square root 13 + 19 Square root 13

Alina [70]

The answer is 6.8383838

3 0

3 years ago