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3 years ago

Please help me ASAP: Answer with : includes / not includes

Mathematics

1 answer:

Elodia [21]3 years ago

3 0

Answer:

Step-by-step explanation:

The interval [4, ∞) all real numbers 4 and greater, whereas the interval (4,∞) not includes the endpoint 4.

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Use the distributive property to rewrite 2(8+x) then simplify

babymother [125]

16+2x

You can’t simplify anymore since there’s no other variable or whole number.

8 0

3 years ago

Read 2 more answers

A random sample of 85 sixth-graders in a large city take a course designed to improve scores on a reading comprehension test. Ba

BartSMP [9]

Answer:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

Step-by-step explanation:

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".

Solution to the problem

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=85-1=84$

We know that the confidence interval is given by:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

3 0

3 years ago

In a fast food study a researcher finds that mean sodium content of 32 Wendy's fish sandwiches is 1080 milligrams with a standar

KiRa [710]

Answer:

Since 95% confidence interval contains 0 we conclude at 95% confidence level that the two means are equal.

Step-by-step explanation:

Given that in a fast food study a researcher finds that mean sodium content of 32 Wendy's fish sandwiches is 1080 milligrams with a standard deviation of 75 milligrams. The mean sodium content of 39 Long John Silver's fish sandwiches is 1120 milligrams with a standard deviation of 100 milligrams

H0: The two means are equal

Ha: The two means are not equal

(Two tailed test at 5% level)

Variable A Variable B

Mean 1080.00 1120.00

SD 75.00 100.00

SEM 13.26 16.01

N 32 39

95% CI: -82.65 to 2.65

Since 95% confidence interval contains 0 we conclude at 95% confidence level that the two means are equal.

7 0

3 years ago

If a 20 ft tree casts a 15ft shadow, how long a shadow is cast

Irina-Kira [14]

Answer:

25 ft

Step-by-step explanation:

c = √a^2 + b^2 = √20^2 + 15^2 = 25ft

Hooke me up with a 5 star and a thanks :)

4 0

2 years ago

Whats x? i don’t understand

rewona [7]

Answer:

The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol. See: Variable.

Step-by-step explanation:

8 0

3 years ago