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3 years ago

Half - life is

Mathematics

1 answer:

Aleonysh [2.5K]3 years ago

8 0

Answer:

the amount of time it takes for approximately 50% of a radioactive atom sample to undergo nuclear decay

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A bag contains 6 green marbles, 5 blue, and 9 red. What is the probability that you will select two green marbles from the bag?

kogti [31]

Answer:

2/20

Step-by-step explanation:

if you add all of the marbles you will get 20 marbles in total.

8 0

3 years ago

.The price of a MP3 Player decreases from $382 to $261.50.find the percentage decrease in its price

FinnZ [79.3K]

The percent of change = ((new value - old value) / old value) × 100%

Our new value = $261.50

Our old value = $382

Plug our values into the equation above.

(($261.50 - $382) / $382) × 100% = -31.54%

8 0

4 years ago

Read 2 more answers

Graph ARST with vertices R(6, 6), S(3, -6), and T(0, 3) and its image after a

padilas [110]

Answer:

The answer is the second figure and the vertices of Δ R'S'T' are:

R' = (-6 , 6) , S' = (-3 , -6) , T' = (0 , 3)

Step-by-step explanation:

* Lets revise some transformation

- If point (x , y) reflected across the x-axis

∴ Its image is (x , -y)

- If point (x , y) reflected across the y-axis

∴ Its image is (-x , y)

- If point (x , y) reflected across the line y = x

∴ Its image is (y , x)

- If point (x , y) reflected across the line y = -x

∴ Its image is (-y , -x)

- Now we can solve the problem

∵ R = (6 , 6) , S = (3 , -6) , T = (0 , 3), they are the vertices of ΔRST

- The triangle RST is reflected over the y-axis

- According to the rule above the signs of x-coordinates will change

∵ R = (6 , 6)

∴ Its image is (-6 , 6)

∵ S = (3 , -6)

∴ Its image is (-3 , -6)

∵ T = (0 , 3)

∴ Its image is (0 , 3)

* Now lets look to the figure to find the correct answers

- The image of Δ RST is ΔR'S'T'

∵ The vertices of the image of ΔRST are:

R' = (-6 , 6) , S' = (-3 , -6) , T' = (0 , 3)

* The answer is the second figure

7 0

3 years ago

An appliance manufacturer claims to have developed a compact microwave oven that consumes a mean of no more than 250 W. From pre

Shtirlitz [24]

Answer:

Null Hypothesis, $H_0$ : $\mu \leq$ 250 W

Alternate Hypothesis, $H_A$ : $\mu$ > 250 W

Step-by-step explanation:

We are given that an appliance manufacturer claims to have developed a compact microwave oven that consumes a mean of no more than 250 W.

They take a sample of 20 microwave ovens and find that they consume a mean of 257.3 W.

Let $\mu$ = mean power consumption of microwave ovens.

So, Null Hypothesis, $H_0$ : $\mu \leq$ 250 W

Alternate Hypothesis, $H_A$ : $\mu$ > 250 W

Here, null hypothesis states that the mean power consumption of microwave ovens is no more than 250 W.

On the other hand, alternate hypothesis sates that the mean power consumption of microwave ovens is more than 250 W.

The test statistics that would be used here is One-sample z test statistics as we know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

Hence, this would be the appropriate hypotheses to determine if the manufacturer's claim appears reasonable.

5 0

4 years ago

Jeremiah plans on building a 5 meter long garden walkway that is paved with square stones that measure " $ meter on each side. T

larisa86 [58]

Complete question :

Jeremiah plans on building a 5 meter long garden walkway that is paved with square stones that measure " 5/6 meter on each side. There will be no spaces between the stones. How many stones will be needed to complete the garden walkway?

Answer:

Step-by-step explanation:

Given that:

Length of square block to be used = 5/6 meters

Length of garden. Walkway = 5 m

Since length of walkway is the same on both sides, then the Total length = 5m + 5m = 10 meters

Number of square stones required :

Total length of walkway / side length of stones to be used

= 10 meters ÷ (5/6) meters

= 10 * 6/5

= 60 / 5

= 12 stones

8 0

3 years ago