10 ft

Mathematics

1 answer:

muminat3 years ago

3 0

10+8+8.9+4=30.9
Rounded to the nearest tenth is 30ft

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Ned help please ASAP!!!!!

Lubov Fominskaja [6]

The answer would be a (not too sure) but it makes a little bit sense

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2 years ago

Suppose that a standardized biology exam has a mean score of 80% correct, with a standard deviation of 3. The school administrat

NemiM [27]

Answer:

The 99% confidence interval is between 62.36%(lower bound) and 89.64%(upper bound).

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 zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

A sample of 65 students from the freshmen class is used and a mean score of 76% correct is obtained.

This means that $n = 65, \pi = 0.76$

99% confidence level

So $\alpha = 0.005$ , z is the value of Z that has a pvalue of $1 - \frac{0.005}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.76 - 2.575\sqrt{\frac{0.76*0.24}{65}} = 0.6236$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.76 + 2.575\sqrt{\frac{0.76*0.24}{65}} = 0.8964$

0.6236*100 = 62.36%

0.8964*100 = 89.64%

The 99% confidence interval is between 62.36%(lower bound) and 89.64%(upper bound).

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2 years ago

Ellen has a bag with 3 red marbles and 2 blue marbles in it. She is going to randomly draw a marble from the bag 300 times, putt

sweet [91]

Answer:

No. of times Ellen draws a blue marble = 120

Step-by-step explanation:

No. of red marbles = 3

No. of blue marbles = 2

$\text{Probability of drawing a blue marble = }\frac{\text{No. of possible outcomes}}{\text{Total no. of outcomes}}\\\\P(B)=\frac{2}{5}\\\\No. of draws (n) = 300\\\text{So, total probability = }n\times P(B)\\\\=100\times \frac{2}{5}=120.$