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3 years ago

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Set of average city temperatures in April are normally distributed with a mean of 19.7°C and a standard deviation of 2°C. The av

erage temperature of Cairo is 21.4°C. What proportion of average city temperatures are the higher than that of Cairo?

1 answer:

Kay [80]3 years ago

3 0

Answer:

The answer is "19.77%"

Step-by-step explanation:

Given:

$\mu = 19.7\\\\ \sigma = 2\\\\\to P(x >21.4 ) = 1 - P(x< 21.4)\\\\$

$= 1 - [\frac{P(x -\mu)}{ \sigma }< \frac{(21.4-19.7)}{2}]\\\\= 1 - P(z < 0.85)\\\\= 1 - 0.8023\\\\=0.1977\\\\=19.77\%$

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3 years ago

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NNADVOKAT [17]

Answer:

Plane's speed is 150 miles/hour

Step-by-step explanation:

Let the plane's airspeed be x

Speed of wind is 30 miles/hour

When a plane flew with the wind , Speed = (x+30)

So, the speed plain with wind on going = (x+30)

Since we are given that on returning plane fly against the wind .

So,When a plane flew against the wind , Speed = (x-30)

So, the speed plain against wind on returning = (x-30)

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So, time on going $=\frac{720}{(x+30)}$

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Now we are given that the total time for the whole trip (going + returning) = 10 hours.

So, $\frac{720}{(x+30)}+\frac{720}{(x-30)}=10$

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$720x-21600+720x+21600=10(x+30)(x-30)$

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So, the plane's speed is 150 miles/hour

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