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3 years ago

SOLVE THIS AND GET 30 POINTS AND BRAINLY!!!!!!!!!!!!!

Mathematics

2 answers:

Dmitry_Shevchenko [17]3 years ago

5 0

Answer:

11. 2:23 2/56

12. 5\67

13. 45/47

14. 55/78

Step-by-step explanation:

poizon [28]3 years ago

4 0

Answer:

2:23 2/56

5\67

45/47

55/78

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Which shape is a Parallelogram?

mariarad [96]

The top left is the correct answer, because the sides are parallel.

Hope this helps!

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3 years ago

Give an example of how you use positive and negative numbers, and explain the meaning of 0 in your example.

EastWind [94]

Answer:

Meanings of the numbers:

Most numbers represent an amount. Positive numbers represent above zero. Zero is the only number that does not represent an amount. It means nothing. When you go lower than nothing, you are in the negative numbers. Negative numbers represent absent values pretty much.

How I would use them in every day life:

I would use positive numbers to represent... maybe something I'm trying to get at a store. Ex: 4 bananas

I would use negative numbers to... maybe look at the temperature. Ex: -16 degrees Fahrenheit. Negative numbers are in temperature all the time.

Hope this helps! (^-^)

6 0

3 years ago

A doctor wants to estimate the mean HDL cholesterol of all 20- to 29-year-old females. The number of subjects needed to estima

Ludmilka [50]

Answer:

$n=(\frac{1.64(14.7)}{3})^2 =64.57 \approx 65$

So the answer for this case would be n=65 rounded up to the nearest integer

And the sample size would decrease by 160-65=95 subjects

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

ME represent the margin of error

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

2) Solution to the problem

Since the new Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$