Mathematics: Acompany has developed a new type of light bulb, and wants to estimate its mean lifetime. a simple random sample of 12 bulbs had a sample mean lifetime of 673 hours with a sample standard deviation of 75 hours. it is reasonable to believe that the population is approximately normal. find the lower bound of the 95% confidence interval for the population mean lifetime of all bulbs manufactured by this new process.

25 Yards, three ribbons, so 25*3, thats 75 yards.Convert 75 yards to Inches, you get 2700 inches, divide 2700 by 22.You get 122.72 Repeating, round up.Your Answer is A, 123...

Acompany has developed a new type of light bulb,

Ответ:

ijeomaokoro2264

15.03.2022

Mathematics

625.35

Step-by-step explanation:

Given : Sample size : n= 12, which is less than 30 , so we use t-test.

Sample mean : $\overlien{x}=673\text{ hours}$

Standard deviation : $\sigma=75\text{ hours}$

Significance level : 1-0.95=0.05

Critical value : $t_{(n-1,\alpha/2)}=t_{(11,0.025)}=\pm2.201$

The confidence interval for population mean is given by :-

$\overline{x}\pm t_{(n-1,\alpha/2)}\dfrac{\sigma}{\sqrt{n}}$

$=673\pm(2.201)\times\dfrac{75}{\sqrt{12}}\\\\\approx673\pm47.65\\\\=(625.35,\ 720.65)$

Hence, the lower bound of the 95% confidence interval for the population mean lifetime of all bulbs manufactured by this new process = 625.35

0,0(0 оценок)

Ответ:

Ответ:

Ask your question to the AI advisor

More tips

Answers on questions: Mathematics

Ask an AI advisor a question