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1 year ago

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A scientist planted seeds in 4 sections of soil for an experiment. not all of the seeds grew into plants. after 20 days, the sci

entist counted the number of plants in each of the 4 sections.

1 answer:

a_sh-v [17]1 year ago

4 0

I think you would multiply 20 × 4 and the answer would be 80 that the scientist counted the number of plants in each 4 sections after 20 days.

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How much water is in an empty glass that is 10cm high and has a diameter of 5cm

Lilit [14]

Answer:

How much water is in an empty glass that is 10cm high and has a diameter of 5 cm ?

= 196,25 cm

Step-by-step explanation:

diameter = 5 cm

radius = 1/2 × diameter

radius = 1/2 × 5 = 2,5

How much water is in an empty glass that is 10cm high and has a diameter of 5 cm?

= π × r × r × high

= 3,14 × 2,5 × 2,5 × 10

= 196,25 cm

4 0

1 year ago

Find the x value 2x=6

sleet_krkn [62]

Answer:

x = 3

Step-by-step explanation:

2x = 6

x = 3 (Because we divide on both sides by 2 so that the x is by itself, 6/2 = 3)

7 0

2 years ago

Read 2 more answers

The town librarian bought a combination of new-release movies on DVD for $20 and classic movies on DVD for $8. Let x represent t

Galina-37 [17]

Answer:

x = 1, y = 60

Step-by-step explanation:

Value of new-releases (x) = $20 each

Value of classic (y) = $8 each

Total budget = $500

Equation : 20x + 8y = 500

The librarian wants to purchase maximum DVDs. She can get more DVDs of classic movies for $8 as they are less costly.

Lets assume the librarian buys at least one new-release DVD.

x=1

20x + 8y = 500

8y + 20(1) = 500

y = 60

<em>Therefore, in a budget of $500, the librarian can purchase 60 classic movies and 1 new-release.</em>

!!

8 0

1 year ago

6 tractors take 10days to collect the harvest. How long would it take 18 tractors to do the same amount of work?

Nutka1998 [239]

This is a question of proportionality. However, it is not direct proportionality as it is expected that as the number of tractors increases, the work is finished faster as opposed to fewer number of tractors. This is referred to as inverse proportionality.

Therefore;
6 tractors ----- 10 days
18 tractors --- x days

Then,
x = (6*10)/18 = 10/3 days = 3 days, and 8 hours.

This means that 18 tractors will take 3 days and 8 hours to collect the same harvest.

6 0

1 year ago

A pharmaceutical company proposes a new drug treatment for alleviating symptoms of PMS (premenstrual syndrome). In the first sta

Akimi4 [234]

Answer:

95% confidence interval for p, the true proportion of all women who will find success with this new treatment is [0.238 , 0.762].

Step-by-step explanation:

We are given that a pharmaceutical company proposes a new drug treatment for alleviating symptoms of PMS (premenstrual syndrome).

In the first stages of a clinical trial, it was successful for 7 out of the 14 women.

Firstly, the pivotal quantity for 95% confidence interval for the true proportion is given by;

P.Q. = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = sample proportion of women who find success with this new treatment = $\frac{7}{14}$ = 0.50

n = sample of women = 14

<em>Here for constructing 95% confidence interval we have used One-sample z proportion statistics.</em>

So, 95% confidence interval for the true proportion, p is ;

P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5%

level of significance are -1.96 & 1.96}

P(-1.96 < $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < 1.96) = 0.95

P( $-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < ${\hat p-p}$ < $1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.95

P( $\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < p < $\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.95

<u />

<u>95% confidence interval for p</u> = [ $\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ , $\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ]

= [ $0.50-1.96 \times {\sqrt{\frac{0.50(1-0.50)}{14} } }$ , $0.50+1.96 \times {\sqrt{\frac{0.50(1-0.50)}{14} } }$ ]

= [0.238 , 0.762]

Therefore, 95% confidence interval for p, the true proportion of all women who will find success with this new treatment is [0.238 , 0.762].

4 0

1 year ago