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2 years ago

I need help please????

Mathematics

2 answers:

andrew-mc [135]2 years ago

6 0

7(34-3(2+1))
7(34-3•3)
7(34-9)
7•25
175
Hope this helps :)

mezya [45]2 years ago

5 0

Answer:

112

Step-by-step explanation:

Just solve it easy peasy

$7[(25+9)-3(2-1)]$

First solve the inner brackets

$7[(34)-3(3)]\\7[25-9]$

Now the other brackets

$7[25-9]\\7[16]\\112$

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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".

$\bar X =4.97$ represent the sample mean

$\mu$ population mean (variable of interest)

s=0.0461 represent the sample standard deviation

n=19 represent the sample size

Confidence interval

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:

$df=n-1=19-1=18$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,18)".And we see that $t_{\alpha/2}=2.10$