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3 years ago

A rectangle has an area of 126 m2 and a width of 7 m. What is its length?

Mathematics

2 answers:

Lorico [155]3 years ago

8 0

126 divided by 7 equals 18

18 m

Kobotan [32]3 years ago

6 0

To find the length divide the area by the width

126/7= 18

check your work to make sure 18 is the length

18*7= 126

Since 18 * 7 does equal 126, 18 is your answer :)

You might be interested in

1x10 to the fifth power over 4x10 to the negative faith power given on scientific notation

MissTica

Answer:

$2.5*10^{8}$

Step-by-step explanation:

<u><em>The correct question is</em></u>

1x10 to the fifth power over 4x10 to the negative fourth power given on scientific notation

we know that

To divide two numbers in scientific notation, divide their coefficients and subtract their exponents.

we have

$\frac{1*10^{5}}{4*10^{-4}}=(\frac{1}{4})*10^{5+4} =0.25*10^{9}= 2.5*10^{8}$

8 0

3 years ago

Assume the sample variances to be continuous measurements. Find the probability that a random sample of 25observations, from a n

konstantin123 [22]

Answer:

a) $P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

b) $P(13.848$ Step-by-step explanation:

Previous concepts

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

For this case we assume that the sample variance is given by $S^2$ and we select a random sample of size n from a normal population with a population variance $\sigma^2$ . And we define the following statistic:

$T = \frac{(n-1) S^2}{\sigma^2}$

And the distribution for this statistic is $T \sim \chi^2_{n-1}$

For this case we know that n =25 and $\sigma^2 = 6$ so then our statistic would be given by:

$\chi^2 = \frac{(n-1)S^2}{\sigma^2}=\frac{24 S^2}{6}= 4S^2$

With 25-1 =24 degrees of freedom.

Solution to the problem

Part a

For this case we want this probability:

$P(S^2 > 9.1)$

And we can multiply the inequality by 4 on both sides and we got:

$P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

And we can use the following excel code to find it: "=1-CHISQ.DIST(36.4,24,TRUE)"

Part b

For this case we want this probability:

$P(3.462 < S^2$

If we multiply the inequality by 4 on all the terms we got:

$P(3.462*4 < 4S^2 < 4*10.745)= P(13.848< \chi^2$ And we can find this probability like this: $P(13.848$ And we use the following code to find the answer in excel: "=CHISQ.DIST(42.98,24,TRUE)-CHISQ.DIST(13.848,24,TRUE)"