Quadratic equation x2+x+9=0

Answer:

a) The standard score associated with a gestation period of 13.8 months is of [tex]Z = -1[/tex]

b) 34% of whale pregnancies will have a gestation period between 13.8 and 15 months.

c) Since when [tex]X = 21[/tex], [tex]Z = 5 \geq 2[/tex], it would be unusual for a whale to have a gestation period of 21 months.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

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

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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.

If [tex]Z \geq 2[/tex] or [tex]Z \leq -2[/tex], the measure X is considered to be unusual.

According to a website, the mean gestation period for a whale is 15 months. Assume the distribution of gestation periods is Normal with a standard deviation of 1.2 months.

I corrected to 1.2 because it is what makes sense considering the questions.

This means that [tex]\mu = 15, \sigma = 1.2[/tex]

a. Find the standard score associated with a gestation period of 13.8 months

This is Z when X = 13.8. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{13.8 - 15}{1.2}[/tex]

[tex]Z = -1[/tex]

The standard score associated with a gestation period of 13.8 months is of [tex]Z = -1[/tex]

b. Using the Empirical Rule and your answer to part a, what percentage of whale pregnancies will have a gestation period between 13.8 and 15 months?

The standard score associated with a gestation period of 13.8 months is of [tex]Z = -1[/tex], which means that it is one standard deviation below the mean.

The normal distribution is symmetric, which means that of the approximately 68% of measures within one standard deviation of the mean, 68%/2 = 34% are within one standard deviation below the mean(in this case, 13.8) and the mean(in this case 15), and 34% are within the mean and one standard deviation above the mean.

So 34% of whale pregnancies will have a gestation period between 13.8 and 15 months.

c. Would it be unusual for a whale to have a gestation period of 21 months? Why or why not?

Let's find the z-score

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{21 - 15}{1.2}[/tex]

[tex]Z = 5[/tex]

Since when [tex]X = 21[/tex], [tex]Z = 5 \geq 2[/tex], it would be unusual for a whale to have a gestation period of 21 months.

Answer:

A,C,D,F

Step-by-step explanation:

Answer:

I believe The answer is D

Step-by-step explanation:

I believe this because If you write the 12's as an exponent it will be 12*4 and the 3's as an exponent will be 3*4. Now just add in the remaining numbers:

12*4 +  7( 3*4 + 3)

Answer:

yes

Explanation:

9514 1404 393

Answer:

  (a)  Yes

Step-by-step explanation:

Two angles of one triangle have the same measures as two angles of the other triangle. The triangles are similar by the AA similarity postulate.

Answer:

63.62

Step-by-step explanation:

pie X r^2

Answer:

option c buddy!!!.....

Answer:

B

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

because they are telling you that the 7th graders were randomly chosen out of everyone who rides in a car to school to be fractioned out.

Answer:

This is your answer ☺️☺️☺️

Answer:

65

Step-by-step explanation:

40+75=115

180-115=65

If this is an triangle

Answer:

The answer is x= 7/30

Answer:

125 I think

Hope this helps

Answer:

Step-by-step explanation:

False

Answer:

Step-by-step explanation:

the answer is 11x^2-14x+11 umm thats  what i got    

( 9x² - 10x + 1 ) - (-2x² + 4x - 10 )

9x² + 2x² = 11x²

-10x - 4x = -14x

1 - (-10) = 1 + 10 = 11

so the answer is

11x² - 14x + 11

Answer:

increasing sequence of +7

Step-by-step explanation:

please mark brainiest

please give 5 stars

thank you

Answer:

5.61

Step-by-step explanation:

66/22 = 3

3×1.87 = 5.61

Answer:

[tex]\huge\boxed{\sf x = 3 }[/tex]

Step-by-step explanation:

If the measure of :

∠CBD = 5 ( 7x + 15 )

Also,

∠CBD = 180°

Then,

5 (7x + 15) = 180

35x + 75 = 180

Subtract 75 to both sides

35x = 180 - 75

35x = 105

Divide both sides by 35

x = 105 / 35

x = 3

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Here's what we know:

n + d = 20 (there are a total of 20 nickels and dimes)

.05n + .1d = 1.4 (total change equals $1.40)

There are a couple of ways to solve this. You can go the elimination method by multiplying the second equation by an amount to get rid of a variable, or we can go substitution by isolating a variable in the first equation. I'll go with elimination in this case:

-10(.05n + .1d = 1.4) this will cause the d-variable to equal 0:

n  +  d = 20

-.5n - d = -14

------------------

.5n = 6

n = 12

Now that we know n, we can solve for d:

12 + d = 20

d = 8

Check:

.05 * 12 + .1 + 8 = 1.4

.6 + .8 = 1.4

1.4 = 1.4

Step-by-step explanation:

Answer:

False

Step-by-step explanation:

Hope I helped :)

1064 x

19

________

20216 legos

Sharon has 20216 legos

Answer:

47.12

Step-by-step explanation:

Answer:

9

Step-by-step explanation:

18 x 1/2

18/2

9

Answer: 9

Step-by-step explanation:

Parenthesis first, so 8+10 =18 .

18 multiplied by 1/2 = 9

Answer:

56

Step-by-step explanation:

Answer:

1:5

Step-by-step explanation:

13cm: 65cm = 13cm/65cm =13/65 = 1/5= 1:5

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Answer: I know #2 is G

Explanation:

A polygon is a plane figure with at least three STRAIGHT sides and angles.

I hope this helped!

<!> Brainliest is appreciated! <!>

- Zack Slocum

*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆

Answer:

area = 138 m²

Step-by-step explanation:

radius of large circle = 12 m

radius of small circle = 10 m

large circle area = πr² = (3.14)(12²) = 452.16 m²

small circle area = πr² = (3.14)(10²) =314 m²

452.16 - 314 = 138.16 m²

Answer:

Shaded Region? 182in²?

Step-by-step explanation:

Where is the Shaded Region?

but between all The options you gave it to us 182in² have area unit