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dezoksy [38]
2 years ago
10

It takes the hot water faucet 4 times as long to fill a bathtub as it does the cold water faucet. Left on together, the cold and

hot water faucets take 3 minutes to fill the tub. How long will it take the cold water faucet to fill the tub by itself
Mathematics
1 answer:
Debora [2.8K]2 years ago
3 0

If it takes the cold water faucet x minutes to fill 1 tub, then its flow rate is (1 tub)/(x min).

The hot water faucet takes 4 times as long, so its flow rate is (1 tub)/(4x min).

Together, the total flow rate is (1 tub)/(3 min), so we have

\dfrac1x+\dfrac1{4x}=\dfrac13

\implies\dfrac5{4x}=\dfrac13

\implies15=4x

\implies x=\dfrac{15}4\,\text{min}=3\,\text{min}\,45\,\text{sec}

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I need to figure out how to do this problem please r=wp for p
PolarNik [594]
R = wp
p = r/w

anything 2 ask please pm me
3 0
2 years ago
ume that adults were randomly selected for a poll. They were asked if they​ "favor or oppose using federal tax dollars to fund m
Nadya [2.5K]

Answer:

The null and alternative hypothesis for this question is H₀: p = 0.50 and H₁: p ≠ 0.50 respectively.

Hence, option B is correct.

Upper H0​: pequals=0.5, Upper H1​: pnot equals≠0.5

The hypothesis test shows that there is enough evidence to conclude that the proportion of the population that favour the use of federal tax dollars to fund medical research using stem cells obtained from human​ embryos is not 0.50 like that of a coin toss. That is, the politicians claim is false.

Step-by-step explanation:

For hypothesis testing, the first thing to define is the null and alternative hypothesis.

The null hypothesis usually contains the signs =, ≤ and ≥ depending on the directions of the test.

While, the alternative hypothesis usually contains the signs ≠, < and > depending on the directions of the test.

For this question, the politician claims that people​ don't really understand the stem cell issue and their responses to such questions are random responses equivalent to a coin toss. A coin toss has a 50-50 probability, with a proportion 0.5 for heads and another 0.5 for tails.

Hence, the null hypothesis for this question would be that there is evidence to suggest that the proportion of the population that favour the use of federal tax dollars to fund medical research using stem cells obtained from human​ embryos is 0.50 like that of a coin toss. That is, the politicians claim is true.

And the alternative hypothesis is that there is significant evidence to conclude that the proportion of the population that favour the use of federal tax dollars to fund medical research using stem cells obtained from human​ embryos is not 0.50 like that of a coin toss. That is, the politicians claim is false.

Mathematically, if p is the population proportion that favour the use of federal tax dollars to fund medical research using stem cells obtained from human​ embryos.

The null hypothesis is represented as

H₀: p = 0.50

The alternative hypothesis is represented as

H₁: p ≠ 0.50

To do this test, we will use the z-distribution because although, no information on the population standard deviation is known, the sample size is large enough for a z-test statistic to work.

So, we compute the test statistic

z = (x - μ)/σₓ

x = sample proportion = (485)/(485+396) = 0.55 (excluding the ones that were unsure)

μ = p₀ = The proportion we are comparing against = 0.50

σₓ = standard error = √[p(1-p)/n]

where n = Sample size = 485 + 396 = 881

σₓ = √[0.55×0.45/881] = 0.0167609874 = 0.01676

z = (0.55 - 0.50) ÷ 0.01676

z = 2.98 = 2.98

checking the tables for the p-value of this z-statistic

Degree of freedom = df = n - 1 = 881 - 1 = 880

Significance level = 0.10

The hypothesis test uses a two-tailed condition because we're testing in both directions (greater than or less than).

p-value (for z = 2.98, at 0.10 significance level, df = 880, with a two tailed condition) = 0.002882

The interpretation of p-values is that

When the (p-value > significance level), we fail to reject the null hypothesis and when the (p-value < significance level), we reject the null hypothesis and accept the alternative hypothesis.

So, for this question, significance level = 0.10

p-value = 0.002882

0.002882 < 0.10

This means that we reject the null hypothesis, accept the alternative hypothesis & say that there is enough evidence to conclude that the proportion of the population that favour the use of federal tax dollars to fund medical research using stem cells obtained from human​ embryos is not 0.50 like that of a coin toss. That is, the politicians claim is false.

Hope this Helps!!!

6 0
3 years ago
Which value of x makes the equation true? 6(x-3)=4x-7
miskamm [114]

Answer:

hope this helps!

x = 5.5

7 0
3 years ago
Help me with this pks
Vanyuwa [196]

Answer:

f=4

Step-by-step explanation:

-11f = 7(1-2f)+5

step 1 distribute what is outside of the parenthesis to the inside of the parenthesis

-11f=7-14f+5

step 2 combine like terms

-11f=12-14f

step 3 add 14 to each side

3f=12

step 4 divide each side by 3

f=4

8 0
3 years ago
Find the mean of -3,-8,12,-15,9
rosijanka [135]

Answer: -1

Step-by-step explanation:

To find the mean of a set of numbers, you add them all and then divide by how many numbers there are in the set. In this case, it would be -3+-8+12+-15+9=-5

Then divide that by how many numbers there are (5)

-5/5= -1

4 0
2 years ago
Read 2 more answers
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