Mathematics, 27.11.2019 03:31 emalvidrez5205

How much does a sleeping bag cost? let's say you want a sleeping bag that should keep you warm in temperatures from 20°f to 45°f. a random sample of prices ($) for sleeping bags in this temperature range is given below. assume that the population of x values has an approximately normal distribution. 35 85 105 40 100 50 30 23 100 110 105 95 105 60 110 120 95 90 60 70 (a) use a calculator with mean and sample standard deviation keys to find the sample mean price x and sample standard deviation s. (round your answers to two decimal places.) x = $ 79.4 correct: your answer is correct. s = $ 30.62 correct: your answer is correct. (b) using the given data as representative of the population of prices of all summer sleeping bags, find a 90% confidence interval for the mean price μ of all summer sleeping bags. (round your answers to two decimal places.)

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Answer from: SamaHafiz8984

a) Sample Mean = 79.4

Sample standard deviation = 30.62

b) 90% Confidence interval: (67.56 ,91.24)

Step-by-step explanation:

We are given the following in the question:

Prices for sleeping bags has an approximately normal distribution.

We are given the following sample:

35, 85, 105, 40, 100, 50, 30, 23, 100, 110, 105, 95, 105, 60, 110, 120, 95, 90, 60, 70

Formula:

$\text{Standard Deviation} = \sqrt{\displaystyle\frac{\sum (x_i -\bar{x})^2}{n-1}}$

where x_i are data points, $\bar{x}$ is the mean and n is the number of observations.

$Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}$

$Mean =\displaystyle\frac{1588}{20} = 79.4$

Sum of squares of differences = 1971.36 + 31.36 + 655.36 + 1552.36 + 424.36 + 864.36 + 2440.36 + 3180.96 + 424.36 + 936.36 + 655.36 + 243.36 + 655.36 + 376.36 + 936.36 + 1648.36 + 243.36 + 112.36 + 376.36 + 88.36 = 17816.8

$S.D = \sqrt{\displaystyle\frac{17816.8}{19}} = 30.62$

b) 90% Confidence interval:

$\bar{x} \pm t_{critical}\displaystyle\frac{s}{\sqrt{n}}$

Putting the values, we get,

$t_{critical}\text{ at degree of freedom 19 and}~\alpha_{0.10} = \pm 1.7291$

$79.4 \pm 1.73(\displaystyle\frac{ 30.62}{\sqrt{20}} ) = 79.4 \pm 11.84 = (67.56 ,91.24)$

Answer from: Quest

this story was prepared by jim

mccullaugh in los angeles and

al stewart in new york.

new york the colossal success of "top gun" appears to have dramatically altered madison avenue's

perception of corporate sponsorship

of home video projects.

the paramount home video re- lease, featuring a 60- second diet

pepsi spot, was by no means the

first prerecorded video to carry an advertiser's plug, but it was the

first major theatrical release to do so. in the aftermath of the title's

success, paramount is widely ex- pected to ink a similar deal for

"crocodile dundee" or "star trek

iv" or both.

corporate america's new attraccds push british

recording sales

to 19% gain

london fueled by the compact

disk boom, the value of u.k. manu- facturer shipments of recordings

rose 19% in the 12 -month period ended march 1987, according to the

british phonographic industry.

total value of u.k. shipments for

the period was $755 million for all

configurations. (all value figures

are based on an exchange rate of

$1.68 to the pound sterling.)

cd sales totaled 10.7 million units

worth $121.3 million- compared

with 3.7 million units worth $39.5

million in the prior 12 months -and

accounted for two -thirds of the

overall gain in trade value. at present growth rates, says the bpi, cd

sales for calendar 1987 will reach 20

(continued on page 79)

step-by-step explanation:

Answer from: Quest

answer: 5100 just subtract

step-by-step explanation:

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