6x -3=-18 + 2х what doe that equal !!!!!

There are 52 weeks in a year. Each have one Monday. Leap years have a total of 366 days. There are 7 days of the week. Monday is one of them, so it'll be a 1/7 chance.

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3 years ago

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airp

Kruka [31]

Answer:

$6.76-2.01\frac{2.55}{\sqrt{50}}=6.03$

$6.76+2.01\frac{2.55}{\sqrt{50}}=7.49$

The 95% confidence interval would be given by (6.03;7.49)

Step-by-step explanation:

Notation

$\bar X$ represent the sample mean

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n=50 represent the sample size

Solution

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

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

We can calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=6.76$

The sample deviation calculated $s=2.55$

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

$df=n-1=50-1=49$

We assume a standard confidence level of 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-T.INV(0.025,49)".And we see that $t_{\alpha/2}=2.01$