Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard devia
1 answer:
Answer:
Where and
So then we can find in the normal standard distribution or in excel a value of Z who accumulates 0.25 of the area below and 0.75 of the area above. We can use the following excel code for example:
="NORM.INV(0.25,0,1)"
And we got = z= -0.674.
So the value of height that separates the bottom 25% of data from the top 75% is -0.674 °C.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the readings at freezing of a population, and for this case we know the distribution for X is given by:
Where and
So then we can find in the normal standard distribution or in excel a value of Z who accumulates 0.25 of the area below and 0.75 of the area above. We can use the following excel code for example:
="NORM.INV(0.25,0,1)"
And we got = z= -0.674.
So the value of height that separates the bottom 25% of data from the top 75% is -0.674 °C.
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The answer is 19.4
Most of the time when you try to find a missing length of a right triangle you use Pythagorean theorem. Pythagorean theorem is A squared plus B squared equals C squared. C squared is always going to be the longest length/diagonal line otherwise known as your hypotenuse. In this case the ladder is the hypotenuse. So instead of adding five squared +20 squared you’re going to square 20 and then subtract five squared to get the missing length which would be B squared and then you have to find the square root of B squared. So 20 squared is 4000. 5squared is 25 400-25 = 375 square root of 375 is about 19.4.
Most of the time when you try to find a missing length of a right triangle you use Pythagorean theorem. Pythagorean theorem is A squared plus B squared equals C squared. C squared is always going to be the longest length/diagonal line otherwise known as your hypotenuse. In this case the ladder is the hypotenuse. So instead of adding five squared +20 squared you’re going to square 20 and then subtract five squared to get the missing length which would be B squared and then you have to find the square root of B squared. So 20 squared is 4000. 5squared is 25 400-25 = 375 square root of 375 is about 19.4.