Can anyone help me pleassseeee!

2/3 times 4/7 Plz thx

vichka [17]

Answer:

8/21

Brainliest? :)

Step-by-step explanation:

4 0

3 years ago

Tori has a one-gallon container to fill with lemonade. She uses the standard recipe. How much concentrate does she need? (one ga

xxMikexx [17]

Answer:

1/4 of a gallon of concentrate

Step-by-step explanation:

128 ounces / 4 = 32 ounces

7 0

3 years ago

A spring has natural length 0.75 m and a 5 kg mass. A force of 8 N is needed to keep the spring stretched to a length of 0.85 m.

I am Lyosha [343]

Use Hooke's law to find the spring constant. If it takes 8N to stretch the spring by 0.1m, then

$8\text{ N}=k(0.1\text{ m})\implies k=80\dfrac{\text N}{\text m}$

I'm going to assume the spring is fixed to a ceiling, and that any stretching in the downward direction counts as movement in the positive direction. The spring's motion is then modeled by

$y''(t)+80y(t)=0$

where $y(t)$ is the position of the spring's free end as it moves up and down. Solving this is easy enough: the characteristic solution will be

$y(t)=C_1\cos4\sqrt5t+C_2\sin4\sqrt5t$

Given that the spring is stretched to a length of 1m (a difference of 0.25m from its natural length), and is released with no external pushing or pulling, we have the two initial conditions $y(0)=\dfrac14$ and $y'(0)=0$ .

$y(0)=\dfrac14\implies\dfrac14=C_1\cos0+C_2\sin0\implies C_1=\dfrac14$
$y'(0)=0\implies 0=-4\sqrt5C_1\sin0+4\sqrt5C_2\cos0\implies C_2=0$

So the spring's motion is dictated by the function

$y(t)=\dfrac14\cos4\sqrt5t$

8 0

3 years ago

For bone density scores that are normally distributed with a mean of 0 and a standard deviation of 1, find the percentage of sco

Alex787 [66]

Answer:

a) $P(Z>2)$

For this case we can use the normal standard table or excel and the complement rule and we got:

$P(Z>2) =1-P(Z$

b) $P(Z$

For this case we can use the normal standard table or excel and we got:

$P(Z$

c) $P(-2$

And we can find this probability with this difference:

$P(-2$

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".

Part a

Let Z the random variable that represent the bone density scores of a population, and for this case we know the distribution for X is given by:

$Z \sim N(0,1)$

Where $\mu=0$ and $\sigma=1$

We are interested on this probability

$P(Z>2)$

For this case we can use the normal standard table or excel and the complement rule and we got:

$P(Z>2) =1-P(Z$

Part b

We are interested on this probability

$P(Z$

For this case we can use the normal standard table or excel and we got:

$P(Z$

Part c: not significant (or less than 2 standard deviations away from the mean).

For this case we want this probability:

$P(-2$

And we can find this probability with this difference:

$P(-2$

6 0

3 years ago

From January to June, a company spent $60.00 per month on office supplies. In July, the price of office supplies increased by 15

pochemuha

The company would spend $69.00 a month on office supplies for the rest of the year.

5 0

3 years ago

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