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2 years ago

[Choose} PLEEASE HELP

Mathematics

2 answers:

matrenka [14]2 years ago

4 0

Answer:

experimental study

Step-by-step explanation:

observational study: no variable is controlled by researchers

experimental study: a variable is controlled by researchers

survey: a survey is similar to a poll

Mumz [18]2 years ago

4 0

Answer:

i think the second one

Step-by-step explanation:

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Pls help me answer this :'(

anzhelika [568]

Answer:

I believe the answer is D :)

4 0

3 years ago

SSHA scores Here are the scores on the Survey of Study Habits and Attitudes (SSHA) for 18 first-year college women:154 109 137 1

mihalych1998 [28]

Answer:

Women has better study habit than men.

Step-by-step explanation:

For knowing who has better study habits and attitudes toward learning we have to find the mean of both the women and men data.

The first step is that we only take first 18 values of both women(X) and men(Y) data, to make them of same length

Mean is used to measure the central tendency of data which represents the whole data in the best way. It can be found as the ratio of the sum of all the observations to the total number of observations.

Calculating all values:

$\bar{X}$ = 141.0556

$\bar{Y}$ = 121.25

Thus, women has better study habit than men. Since Mean of X is larger than Mean of Y.

5 0

3 years ago

Find the sum of 8 + 11 + 14 + ... + 602 + 605.

Sedbober [7]

Answer:

1,240

Step-by-step explanation:

Okay so, 8+11=19 then 19+14= 33. 33+602= 635 Finally, 635+605 should = 1,240.

8 0

2 years ago

Read 2 more answers

Pls help me solve this question, also include step by step calculation ya. Thks

sp2606 [1]

$\displaystyle\\Answer:\ x=\sqrt{2}\ \ \ \ \ x=-\sqrt{2}\ \ \ \ \ x=\frac{ln5}{2}$

Step-by-step explanation:

$5x^2-x^2e^{2x}+2e^{2x}=10$

$Let:\ x^2=t \ \ \ \ \ e^{2x}=v\\Hence,\\5t-tv+2v^2=10\\5t-tv+2v^2-10=10-10\\5t-tv-10+2v^2=0\\t(5-v)-2(5-v)=0\\(5-v)(t-2)=0\\5-v=0\\5-v+v=0+v\\5=v\\5=e^{2x}$

Prologarithmize both parts of the equation:

$ln5=lne^{2x}\\ln5=2x*lne\\ln5=2x*1\\ln5=2x\\$

Divide both parts of the equation by 2:

$\displaystyle\\x=\frac{ln5}{2}$

$t-2=0\\t-2+2=0+2\\t=2\\x^2=2\\x=\sqrt{2} \\x=-\sqrt{2}$

6 0

1 year ago

The half-life of caffeine in a healthy adult is 4.8 hours. Jeremiah drinks 18 ounces of caffeinated

statuscvo [17]

We want to see how long will take a healthy adult to reduce the caffeine in his body to a 60%. We will find that the answer is 3.55 hours.

We know that the half-life of caffeine is 4.8 hours, this means that for a given initial quantity of coffee A, after 4.8 hours that quantity reduces to A/2.

So we can define the proportion of coffee that Jeremiah has in his body as:

P(t) = 1*e^{k*t}

Such that:

P(4.8 h) = 0.5 = 1*e^{k*4.8}

Then, if we apply the natural logarithm we get:

Ln(0.5) = Ln(e^{k*4.8})

Ln(0.5) = k*4.8

Ln(0.5)/4.8 = k = -0.144

Then the equation is:

P(t) = 1*e^{-0.144*t}

Now we want to find the time such that the caffeine in his body is the 60% of what he drank that morning, then we must solve:

P(t) = 0.6 = 1*e^{-0.144*t}

Again, we use the natural logarithm:

Ln(0.6) = Ln(e^{-0.144*t})

Ln(0.6) = -0.144*t

Ln(0.6)/-0.144 = t = 3.55

So after 3.55 hours only the 60% of the coffee that he drank that morning will still be in his body.

If you want to learn more, you can read:

brainly.com/question/19599469

7 0

2 years ago