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3 years ago

What is an extraneous solution?

1 answer:

5 0

An extraneous solution is a solution to a function which does not apply to the original problem. Such as in real life problems, measuring the sides of a shape to determine area or volume. If you solve for x and one of the solutions is a negative number, that would be an extraneous solution, since in real life we cannot have negative inches, centimeters, milliliters, etc.

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Use <, >, or = to compare the following decimals.

TEA [102]

Answer:

A is >

B is >

C is =

I hope this helps you.

7 0

3 years ago

Im pretty bad with coordinates anyone wanna help with an explanation and and answer please? Ty

Salsk061 [2.6K]

Answer:

About 9.4

Step-by-step explanation:

64+25=89

sqr root of 89 is 9.4339

4 0

3 years ago

Round 17.641 to the nearest whole number

vfiekz [6]

The nearest whole number would be 18 because the 6 is greater than 5. Anything greater than five, would most likely be rounded to the nearest whole number. Hope this helped!

8 0

3 years ago

There are 48 students in an elementary statistics class. On the basis of years of experience, the instructor knows that the time

Stella [2.4K]

Answer:

a) 64.06% probability that he is through grading before the 11:00 P.M. TV news begins.

b) The hardness distribution is not given. But you would have to find s when n = 39, then the probability would be 1 subtracted by the pvalue of Z when X = 51.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For the sum of n trials, the mean is $\mu*n$ and the standard deviation is $s = \sigma\sqrt{n}$

In this question:

$n = 48, \mu = 48*5 = 240, s = 4\sqrt{48} = 27.71$

These values are in minutes.

(a) If grading times are independent and the instructor begins grading at 6:50 P.M. and grades continuously, what is the (approximate) probability that he is through grading before the 11:00 P.M. TV news begins?

From 6:50 PM to 11 PM there are 4 hours and 10 minutes, so 4*60 + 10 = 250 minutes. This probability is the pvalue of Z when X = 250. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{250 - 240}{27.71}$

$Z = 0.36$

$Z = 0.36$ has a pvalue of 0.6406

64.06% probability that he is through grading before the 11:00 P.M. TV news begins.

(b) What is the (approximate) probability that the sample mean hardness for a random sample of 39 pins is at least 51?

The hardness distribution is not given. But you would have to find s when n = 39(using the standard deviation of the population divided by the square root of 39, since it is not a sum here), then the probability would be 1 subtracted by the pvalue of Z when X = 51.

5 0

3 years ago

The volume of a cube is 64 centimeters. What is the surface area of the cube?

Andrews [41]

Answer:

Step-by-step explanation:

16 $cm^{2}$

4 0

3 years ago