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3 years ago

12

A submarine dives at an angle of 13 degrees to the surface of the water. The submarine travels at a speed of 760 feet per minute

. About how deep is the sub after 5 min ?

1 answer:

Bad White [126]3 years ago

3 0

5 54r 4e2dwdfftye45dsww32444444re

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Candice is preparing for her final exam in Statistics. She knows she needs an 65 out of 100 to earn an A overall in the course.

sertanlavr [38]

Answer:

a. 72

b. 816

c. 570

d. 30

Step-by-step explanation:

Given the graph is a bell - shaped curve. So, we understand that this is a normal distribution and that the bell - shaped curve is a symmetric curve.

Please refer the figure for a better understanding.

a. In a normal distribution, Mean = Median = Mode

Therefore, Median = Mean = 72

b. We have to know that 68% of the values are within the first standard deviation of the mean.

i.e., 68% values are between Mean Standard Deviation (SD).

Scores between 63 and 81 :

Note that 72 - 9 = 63 and

72 + 9 = 81

This implies scores between 63 and 81 constitute 68% of the values, 34% each, since the curve is symmetric.

Now, Scores between 63 and 81 =

= 68 X 12 = 816.

That means 816 students have scored between 63 and 81.

c. We have to know that 95% of the values lie between second Standard Deviation of the mean.

i.e., 95% values are between Mean 2(SD).

Note that 90 = 72 + 2(9) = 72 + 18

Also, 54 = 63 - 18.

Scores between 54 and 90 totally constitute 95% of the values. So, Scores between 72 and 90 should amount to of the values.

Therefore, Scores between 72 and 90 =

= 570.

That is a total of 570 students scored between 72 and 90.

d. We have to know that 5 % of the values lie on the thirst standard Deviation of the mean.

In this case, 5 % of the values lie between below 54 and above 90.

Since, we are asked to find scores below 54. It should be 2.5% of the values.

So, Scores below 54 =

= 2.5 X 12 = 30.

That is, 30 students have scored below 54.

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Majesty Video Production Inc. wants the mean length of its advertisements to be 26 seconds. Assume the distribution of ad length

Paladinen [302]

Answer:

a) By the Central Limit Theorem, approximately normally distributed, with mean 26 and standard error 0.44.

b) s = 0.44

c) 0.84% of the sample means will be greater than 27.05 seconds

d) 98.46% of the sample means will be greater than 25.05 seconds

e) 97.62% of the sample means will be greater than 25.05 but less than 27.05 seconds

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation(also called standard error) $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this problem, we have that:

$\mu = 26, \sigma = 2, n = 21, s = \frac{2}{\sqrt{21}} = 0.44$

a. What can we say about the shape of the distribution of the sample mean time?

By the Central Limit Theorem, approximately normally distributed, with mean 26 and standard error 0.44.

b. What is the standard error of the mean time? (Round your answer to 2 decimal places)

$s = \frac{2}{\sqrt{21}} = 0.44$

c. What percent of the sample means will be greater than 27.05 seconds?

This is 1 subtracted by the pvalue of Z when X = 27.05. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{27.05 - 26}{0.44}$

$Z = 2.39$

$Z = 2.39$ has a pvalue of 0.9916

1 - 0.9916 = 0.0084

0.84% of the sample means will be greater than 27.05 seconds

d. What percent of the sample means will be greater than 25.05 seconds?

This is 1 subtracted by the pvalue of Z when X = 25.05. So

$Z = \frac{X - \mu}{s}$

$Z = \frac{25.05 - 26}{0.44}$

$Z = -2.16$

$Z = -2.16$ has a pvalue of 0.0154

1 - 0.0154 = 0.9846

98.46% of the sample means will be greater than 25.05 seconds

e. What percent of the sample means will be greater than 25.05 but less than 27.05 seconds?"

This is the pvalue of Z when X = 27.05 subtracted by the pvalue of Z when X = 25.05.

X = 27.05

$Z = \frac{X - \mu}{s}$

$Z = \frac{27.05 - 26}{0.44}$

$Z = 2.39$

$Z = 2.39$ has a pvalue of 0.9916

X = 25.05

$Z = \frac{X - \mu}{s}$

$Z = \frac{25.05 - 26}{0.44}$

$Z = -2.16$

$Z = -2.16$ has a pvalue of 0.0154

0.9916 - 0.0154 = 0.9762

97.62% of the sample means will be greater than 25.05 but less than 27.05 seconds

8 0

3 years ago

Convert 300 g into kilograms

babymother [125]

300 grams = 0.3 kilograms

6 0

3 years ago

Claire says the expression 8x’has three terms: 8, x, and 3. Is she correct? Explain.

KatRina [158]

Answer:

No

Step-by-step explanation:

No because the 8x^3 is all one term since it is not separated by any signs.

8 0

2 years ago

3y=11-2x, 3x=y-11 linear equation solve using the algebraic method check solution

tamaranim1 [39]

Answer:

(x, y) = (- 2, 5)

Step-by-step explanation:

given the 2 equations

3y = 11 - 2x → (1)

3x = y - 11 → (2)

Rearrange (2) expressing y in terms of x

add 11 to both sides

y = 3x + 11 → (3)

Substitute y = 3x + 11 into (1)

3(3x + 11) = 11 - 2x

9x + 33 = 11 - 2x ( add 2x to both sides )

11x + 33 = 11 ( subtract 33 from both sides )

11x = - 22 ( divide both sides by 11 )

x = - 2

Substitute x = - 2 in (3) for corresponding value of y

y = (3 × - 2) + 11 = - 6 + 11 = 5

As a check

substitute x = - 2, y = 5 into (1) and (2) and if the left side equals the right side then these values are the solution.

(1) : left side = (3 × 5) = 15

right side = 11 - (2 × - 2) = 11 + 4 = 15 ⇒ left = right

(2) : left side = (3 × - 2 ) = - 6

right side = 5 - 11 = - 6 ⇒ left = right

solution = (- 2, 5 )

5 0

2 years ago