contestada

Suppose you asked 100 commuters how much they spend each year and obtained a mean of $167 spent on transportation and a standard deviation of $40. Using the 2 SE rule of thumb, calculate a 95% confidence interval for the mean and select the values that come closest to those that would fill the spaces in the following interpretation: we can be 95% confident that the mean amount of money spent on transportation lies between _____ and _____ .

Respuesta :

Cricetus

Answer:

The correct answer is "$159 and $175".

Step-by-step explanation:

The give values are:

Mean,

= $167

Standard deviation,

[tex]\sigma[/tex] = $40

Number of commuters,

n = 100

Now,

⇒ [tex]SE=\frac{\sigma}{\sqrt{n} }[/tex]

On putting the given values, we get

⇒       [tex]=\frac{40}{\sqrt{100} }[/tex]

⇒       [tex]=\frac{40}{10}[/tex]

⇒       [tex]=4[/tex]

By using the 2 SE rule of thumb, we get

= [tex]$(167 - 2\times 4)[/tex]

= [tex]167-8[/tex]

= [tex]159[/tex] ($)

Or,

= [tex](167 + 2\times 4)[/tex]

= [tex]167+8[/tex]

= [tex]175[/tex] ($)

i.e,

$159 and $175

Otras preguntas