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3 years ago

4. A scientist changes the temperature of a solution at a rate of -7°C per minute. How many minutes will it take for

Mathematics

1 answer:

igomit [66]3 years ago

6 0

Answer:

7 minutes

Step-by-step explanation:

The scientist changes the temperature for the solution at a rate of -7°C per minute. We need to find out how long it'll take for the solution's temperature to change from 0°C to -49°C. So, we divide -7 by -49 to find out how long it will take:

-49 / -7 = 7

It will take 7 minutes for the temperature to reach -49°C.

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The US Agency for Healthcare Research and Quality (www.ahrq.gov) reported that in 2010 the mean cost of a stay in a hospital for

zysi [14]

Answer:

We conclude that the population mean cost for a hospital stay for American women aged 18-44 has increased since 2010.

Step-by-step explanation:

We are given that the US Agency for Healthcare Research and Quality reported that in 2010 the mean cost of a stay in a hospital for American women aged 18-44 was $15,200.

A random sample of 400 hospital stays for American women aged 18-44 showed a mean cost of $16,000, with a standard deviation of $5000.

Let $\mu$ = population mean cost for a hospital stay for American women aged 18-44.

SO, Null Hypothesis, $H_0$ : $\mu$ $\leq$ $15,200 {means that the population mean cost for a hospital stay for American women aged 18-44 has reduced or remains same since 2010}

Alternate Hypothesis, $H_A$ : $\mu$ > $15,200 {means that the population mean cost for a hospital stay for American women aged 18-44 has increased since 2010}

The test statistics that will be used here is One-sample t test statistics as we don't know about the population standard deviation;

T.S. = $\frac{\bar X -\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean cost of a stay in a hospital for American women aged 18-44 = $16,000

s = sample standard deviation = $5,000

n = sample of hospital stays = 400

So, test statistics = $\frac{16,000-15,200}{\frac{5,000}{\sqrt{400} } }$ ~ $t_3_9_9$

= 3.20

Now at 5% significance level, the t table gives critical value of 1.645 at 399 degree of freedom for right-tailed test. Since our test statistics is more than the critical value of t as 1.645 < 3.20, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.

Therefore, we conclude that the population mean cost for a hospital stay for American women aged 18-44 has increased since 2010.

8 0

3 years ago

What are the zeros of the polynomial function

Rasek [7]

Answer:

The zeros are 0, -2, and 4.

Step-by-step explanation:

Factor equation into x(x+2)(x-4)=0

Solve.

x+2=0

x=-2

x-4=0

x=4

and do not forget the x in the front, which needs no solving, as it equals zero.

x=0

3 0

3 years ago

Solve 3/4+(1/3 : 1/6)-(-1/2)

Nuetrik [128]

Answer:

Step-by-step explanation:

first you work out what is in the brackets

that is

to give you 2 as you answer

second step rewrite the whole question replacing two in the place of

so you will have

−

(

−

)

thirdly open the brackets with the negative sign outside the bracket that is:

−

(

−

)

so that you get

(or

, basically)

lastly rewrite the whole question

so you will have

, you add all of them ...

EXTRA

you can keep that solution, or you can change it from improper fraction to a mixed number

if you use long division,

with a remainder of

over

doing this by calculator you get 3.25, which is basically

100

8 0

3 years ago

Sandi works for Elizabeth Arden Cosmetics and earns $500 per week salary plus 4% commission on sales over $2,000. If Sandi sold

podryga [215]

To find the amount of money she earned out of the 2733...
You need 4% of 2000 which is...
its 80 which means for every $2000 she sells she earns $80.
She sold just over 2 amounts of 2000 therefore,
her salary is $609.32

3 0

3 years ago

Find 3 consecutive numbers that equal 45

tatyana61 [14]

Answer:

14,15,16

Step-by-step explanation:

Let x be the first number

Consecutive means in a row

x+1 is the second number

x+2 is the third number

x+ x+1 + x+2 = 45

Combine like terms

3x+3 = 45

Subtract 3 from each side

3x+3-3=45-3

3x = 42

Divide each side by 3

3x/3 = 42/3

x =14

The first number is 14

The second number is 14+1 = 15

The third number is 14+2 =16

7 0

3 years ago

Read 2 more answers