Mathematics, 07.05.2020 06:08 jenesis8

The National Center for Education Statistics surveyed a random sample of 4400 college graduates about the lengths of time required to earn their bachelor’s degrees. The mean was 5.15 years and the standard deviation was 1.68 years respectively. Construct a 95% confidence interval for the mean time required to earn a bachelor’s degree by all college students. *

Answers: 3

Show answers

Answers

95% confidence interval for the mean time required to earn a bachelor’s degree by all college students is [5.10 years , 5.20 years].

Step-by-step explanation:

We are given that the National Center for Education Statistics surveyed a random sample of 4400 college graduates about the lengths of time required to earn their bachelor’s degrees. The mean was 5.15 years and the standard deviation was 1.68 years respectively.

Firstly, the pivotal quantity for 95% confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean time = 5.15 years

$\sigma$ = sample standard deviation = 1.68 years

n = sample of college graduates = 4400

$\mu$ = population mean time

Here for constructing 95% confidence interval we have used One-sample z test statistics although we are given sample standard deviation because the sample size is very large so at large sample values t distribution also follows normal.

So, 95% confidence interval for the population mean, $\mu$ is ;

P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5%

level of significance are -1.96 & 1.96}

P(-1.96 < $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ < 1.96) = 0.95

P( $-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

95% confidence interval for $\mu$ = [ $\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $5.15-1.96 \times {\frac{1.68}{\sqrt{4400} } }$ , $5.15+1.96 \times {\frac{1.68}{\sqrt{4400} } }$ ]

= [5.10 , 5.20]

Therefore, 95% confidence interval for the mean time required to earn a bachelor’s degree by all college students is [5.10 years , 5.20 years].

Answer from: Quest

40% off the regular price is the correct answer.

step-by-step explanation:

Answer from: Quest

drive more conversions to your website

conversions are the outcome of your efforts. when a visitor sign up for any newspaper, or fill any form to order a specific product or when your page is shared on social media, all such attempts mean conversions of a website. whenever your desired action is fulfilled, the conversion rate of your website will increase. this increase in your conversion rate will prove that your website is going well. it also confirms that the quality of your website’s marketing was really good.drive more conversion to your website drive more conversions to your website

Another question on Mathematics

Mathematics, 21.06.2019 15:30

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

Answers: 2

Answer

Mathematics, 22.06.2019 00:00

Apack of gum would be considered a(n) necessity luxury item small ticket item unaccountable expense

Answers: 2

Answer

Mathematics, 22.06.2019 03:00

L2.8.2 test (cst): triangles in the figure, pq is parallel to rs. the length of rp is 5 cm; the length of pt is 30 cm; the length of q7 is 60 cm. what is the length of so? o a. 20 cm 0 0 o b. 6 cm o c. 10 cm od. 2 cm 0 previous

Answers: 2

Answer

Mathematics, 22.06.2019 03:20

Circle a has center of (2,3) and a radius of 5 and circle b has a center of (1,4) and a radius of 10. what steps will show that circle a is similar to circle b 1) dilate circle a by a scale factor of 2 2) translate circle a using the rule (x+1,y-1) 3) rotate circle a 180 degrees about the center 4) reflect circle a over the y-axis

Answers: 2

Answer

You know the right answer?

The National Center for Education Statistics surveyed a random sample of 4400 college graduates abou...

Questions