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OLga [1]
3 years ago
7

The battery standby duration (in hours) of a new model of cell phone is known to be normally distributed. Ten pieces of such new

model of cell phone supplied from the manufacturer are randomly chosen and the actual standby durations are recorded as below:
48.2 47.8 45.6 47.2 49.3
51.2 44.2 45.4 49.2 43.6

(a) Calculate the unbiased estimates of population mean and standard deviation of battery standby duration (in hours) of the new cell phone.

(b) The manufacturer claimed that this new model of cell phone has the mean battery standby duration of longer than 46.5 hours. Test at 1% significance level if this claim is true.
Mathematics
1 answer:
Stells [14]3 years ago
3 0

x = number of hours

want to find probability (P) x >= 13

x is N(14,1) transform to N(0,1) using z = (x - mean) / standard deviation so can look up probability using standard normal probability table.

P(x >= 13) = P( z > (13 - 14)/1) = P(z > -1) = 1 - P(z < -1) = 1 - 0.1587 = 0.8413

To convert that to percentage, multiply 100, to get 84.13%

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Step-by-step explanation:

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THerefore you get:cos(F)=\frac{15}{25}\\\\cos(F)=\frac{3}{5}

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Answer:

Silver car

Step-by-step explanation:

It seems pretty hard but it's actually REALLY easy. gas mileage means the number of miles you can go on a particular amount of gallons. But the gallons have to be the same for both cars so that it's fair.

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Answer:

y = \frac{1}{5} x - 2

Step-by-step explanation:

The equation of a line in slope- intercept form is

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I can get you jump started a bit.

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Easy As Pie!

If you need more help, contact me! :)

Hope this Helps!

P.S. Stay Safe!

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