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1 year ago

14

Jorden drives to the store at 30 miles per hour. On her way home she averages only 20 miles per hour. If the total driving time

takes half an hour, how far does she live from the store?

2 answers:

kozerog [31]1 year ago

7 0

Answer:

Rate column: 30, 20.

Distance column: x miles for both.

Step-by-step explanation:

Trava [24]1 year ago

4 0

For this case we have the following definition:
$d = v * t
$
Where,
d: distance
v: speed
t: time
Clearing the time we have:
$t = d / v
$
The total driving time takes half an hour:
$t = d / v1 + d / v2

1.5 = d / 30 + d / 20$
Clearing d we have:
$1.5 * 30 * 20 = 20d + 30d

1.5 * 30 * 20 = 50d

d = (1.5 * 30 * 20) / (50)

d = 18 miles$
Answer:
she lives 18 miles far from the store

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The percentage of body fat of a random sample of 36 men aged 20 to 29 found a sample mean of 14.42. Find a 95% confidence interv

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Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

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$\bar X=14.42$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=6.95$ represent the population standard deviation

n=36 represent the sample size

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

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2 years ago

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Step-by-step explanation:

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