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3 years ago

Which expression is equivalent to -2 1/4÷ (-2/3)

Mathematics

1 answer:

Talja [164]3 years ago

3 0

Answer:

$-2\dfrac{1}{4}\div\left(-\dfrac{2}{3}\right)=\dfrac{27}{8}=3\dfrac{3}{8}}$

Step-by-step explanation:

$-2\dfrac{1}{4}\div\left(-\dfrac{2}{3}\right)\qquad\text{the quotient of two negative numbers is positive}\\\\=2\dfrac{1}{4}\div\dfrac{2}{3}\qquad\text{convert the mixed number to the improper fraction}\\\\=\dfrac{2\cdot4+1}{4}\div\dfrac{2}{3}=\dfrac{9}{4}\div\dfrac{2}{3}\\\\\text{dividing by a fraction is the same as multiplying by its reciprocal.}\\\\=\dfrac{9}{4}\cdot\dfrac{3}{2}=\dfrac{9\cdot3}{4\cdot2}=\dfrac{27}{8}\qquad\text{convert to the mixed number}\\\\=3\dfrac{3}{8}$

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Which statement is always true about a right triangle

Vilka [71]

Answer:

a right angle is an angle of exactly 90° (degrees) .

Step-by-step explanation:

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3 years ago

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Tyana has a collection of hoodies and t-shirts. She has 561 pieces of collected clothing in all. The number of hoodies is twice

Delicious77 [7]

Answer:

187 t-shirts and 374 hoodies.

Step-by-step explanation:

(t is shirts)

561 = t + (2t)

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3 years ago

james went out for a long walk . He walked 3 2/5 of the mile. then he sat down to take rest . After that he walked 5/7 of a mile

kotykmax [81]

Answer:

Altogether James walked $4\frac{4}{35}$ miles.

Step-by-step explanation:

The question involves mixed fractions. Mixed fractions are first converted into proper fractions and then any operation can be performed on them.

Given

Distance of first walk = $3\frac{2}{5}$ of a mile

Distance of second walk = 5/7

In order to find how much he walked altogether, we have to find the sum of both fractions.

$Total\ distance = 3\frac{2}{5}+\frac{5}{7}\\= \frac{17}{5}+\frac{5}{7}\\=\frac{17*7}{5*7} + \frac{5*5}{7*5}\\=\frac{119}{35} + \frac{25}{35}\\=\frac{119+25}{35}\\=\frac{144}{35}\\=4\frac{4}{35}$

Hence,

Altogether James walked $4\frac{4}{35}$ miles.

8 0

3 years ago

According to the Sleep Foundation, the average night’s sleep is 6.8 hours. Assume the standard deviation is .6 hours and that th

Ivan

Answer:

9.18% probability that a randomly selected person sleeps 6 hours or less

Step-by-step explanation:

Problems of normally distributed samples are solved using 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.

In this problem, we have that:

$\mu = 6.8, \sigma = 0.6$