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Vedmedyk [2.9K]
2 years ago
12

Assume that the mean length of a human pregnancy is 269 days. If​ 95% of all human pregnancies last between 249 and 289 ​days, w

hat is the standard deviation of the distribution of lengths of human​ pregnancies? What percent of human pregnancies are expected to last at least 287 ​days?
Mathematics
1 answer:
o-na [289]2 years ago
7 0

Answer:93% not sure

Step-by-step explanation:

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Andrea wants to deposit money into a bank account that earns 4.5% simple interest. Use the formula l=Prt to find the ammount of
AlladinOne [14]
The formula is
I=prt
I interest earned 2800
P amount deposited. ?
R interest rate 0.045
T time 4.5 years
Solve the formula for p by dividing both sides by rt to get
P=I/rt
P=2,800÷(0.045×4.5)
P=13,827.16 round your answer to get 13827

Hope it helps!
4 0
3 years ago
Oof this is probably really simple to most of y'all but I'm out of it.
Lelechka [254]

Answers:

  • angle1 = 156 degrees
  • angle2 = 24 degrees

=======================================================

Explanation:

The two angles form a straight line, which is 180 degrees

Add up the angle expressions and set the sum equal to 180.

(angle1) + (angle2) = 180

(4x) + (x-15) = 180

(4x+x)-15 = 180

5x-15 = 180

5x = 180+15

5x = 195

x = 195/5

x = 39

We use that x value to find each missing angle

  • angle1 = 4x = 4*39 = 156 degrees
  • angle2 = x-15 = 39-15 = 24 degrees

Then notice how angle1+angle2 = 156+24 = 180 to verify the answer.

Side note: Angles that add to 180 are considered supplementary.

6 0
2 years ago
Factor out the coefficient of the variable term The expression 1/10k-7/10 factored is
Goshia [24]

Answer:

The answer: 1/10x (k-7)

Step-by-step explanation:

6 0
3 years ago
What is 13 10/15 in the lowest terms?
olga55 [171]

The answer is below:

13\frac{2}{3}

5 0
3 years ago
The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition. He wants to first deter
VMariaS [17]

Answer:

He must survey 123 adults.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of \pi, and a confidence level of 1-\alpha, we have the following confidence interval of proportions.

\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}

In which

z is the z-score that has a p-value of 1 - \frac{\alpha}{2}.

The margin of error is:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

Assume that a recent survey suggests that about 87​% of adults have heard of the brand.

This means that \pi = 0.87

90% confidence level

So \alpha = 0.1, z is the value of Z that has a p-value of 1 - \frac{0.1}{2} = 0.95, so Z = 1.645.

How many adults must he survey in order to be 90​% confident that his estimate is within five percentage points of the true population​ percentage?

This is n for which M = 0.05. So

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

0.05 = 1.645\sqrt{\frac{0.87*0.13}{n}}

0.05\sqrt{n} = 1.645\sqrt{0.87*0.13}

\sqrt{n} = \frac{1.645\sqrt{0.87*0.13}}{0.05}

(\sqrt{n})^2 = (\frac{1.645\sqrt{0.87*0.13}}{0.05})^2

n = 122.4

Rounding up:

He must survey 123 adults.

6 0
2 years ago
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