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4 years ago

A sample of 4 is selected from a lot of 20 piston rings. How many different sample combinations are possible?

Mathematics

1 answer:

Sunny_sXe [5.5K]4 years ago

3 0

Answer:

Step-by-step explanation:

Sample of 4 is selected: _ _ _ _

Number of possibilities for first selection: 20

Number of possibilities for second selection: 19 (because one was already chosen)

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When 2 less than 3 lots of a number is doubled the result is 5

Vitek1552 [10]

Can you rephrase it? (maybe write it out in numbers?)

4 0

4 years ago

Read 2 more answers

What is the standard error of the sampling distribution of sample proportion?.

storchak [24]

Answer:

√ (p(1-p) / n)

Step-by-step explanation:

Standard Error(SE) of the Sample Proportion: √ (p(1-p) / n). Note: as the sample size increases, the standard error decreases.

Hope this helps you! Feel free to give feedback

5 0

2 years ago

Solve the equation using the distributive property and properties of equality

NeTakaya

Answer:

x = 30

Step-by-step explanation:

1/2(x+6) = 18

Distribute

1/2 x + 3 = 18

Subtract 3 from each side

1/2x +3-3 = 18-3

1/2x = 15

Multiply each side by 2

1/2x*2 = 15*2

x = 30

6 0

3 years ago

Read 2 more answers

Two pools are being drained. To start, the first pool had 3850 liters of water and the second pool had 4370 liters of water. Wat

SashulF [63]

Answer:

(a)

Amount of water in the first pool (in liters) = 3850 liters - 33 liters per minute * x minutes

Amount of water in the second pool (in liters) = 4370 liters - 43 liters per minute * x minutes

(b)

3850 liters - 33 liters per minute * x minutes= 4370 liters - 43 liters per minute * x minutes

Step-by-step explanation:

(a) With x being the minutes after which you want to calculate the amount of water in the pool, to calculate this amount of water you must subtract the water drained from the initial amount of water that the pool contains.

Knowing that, for example, the water from the first pool drains at a rate of 33 liters per minute, then after x minutes, the total water drained will be 33 liters per minute * x minutes. Then:

Amount of water in the first pool (in liters) = 3850 liters - 33 liters per minute * x minutes

Reasoning in the same way:

Amount of water in the second pool (in liters) = 4370 liters - 43 liters per minute * x minutes

(b) Now want to know when the two pools would have the same amount of water. If they have the same amount of water then you can express:

Amount of water in the first pool = Amount of water in the second pool

Replacing the expressions found in (a):

3850 liters - 33 liters per minute * x minutes= 4370 liters - 43 liters per minute * x minutes

5 0

3 years ago

Roberto rowed 20 miles downstream in 2.5 hours. The trip back, however, took him 5 hours. Find the rate that Roberto rows in sti

almond37 [142]

Answer:

Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour

Step-by-step explanation:

Relative Speed

When a body is moving at a constant speed v, the distance traveled in a time t is:

$d=v.t$

When Roberto rows downstream, his speed in still water is added to the speed of the water, making it easier to travel the required distance.

When Roberto rows upstream, his speed in still water is affected by the speed of the water, both are subtracted and the required distance is covered in more time.

Let's call

x = Roberto's rowing speed in still water

y = Speed of the river current

The speed when rowing downstream is x+y, thus the distance traveled is

$d=(x+y).t_1$