(1/2+2/3)÷2 5/6×15-3 1/7

Lengths of full-term babies in the US are Normally distributed with a mean length of 20.5 inches and a standard deviation of 0.9

mash [69]

Answer:

66.48% of full-term babies are between 19 and 21 inches long at birth

Step-by-step explanation:

Normal Probability Distribution:

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

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Mean length of 20.5 inches and a standard deviation of 0.90 inches.

This means that $\mu = 20.5, \sigma = 0.9$

What percentage of full-term babies are between 19 and 21 inches long at birth?

The proportion is the p-value of Z when X = 21 subtracted by the p-value of Z when X = 19. Then

X = 21

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

$Z = \frac{21 - 20.5}{0.9}$

$Z = 0.56$

$Z = 0.56$ has a p-value of 0.7123

X = 19

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

$Z = \frac{19 - 20.5}{0.9}$

$Z = -1.67$

$Z = -1.67$ has a p-value of 0.0475

0.7123 - 0.0475 = 0.6648

0.6648*100% = 66.48%

66.48% of full-term babies are between 19 and 21 inches long at birth

5 0

2 years ago

Please help me! i really need it:( <br>this is geometry btw

loris [4]

Answer:

The answer is A

Step-by-step explanation:

I solved using surface area

7 0

3 years ago

What are the coordinates of the midpoint of the line segment with endpoints 2,5 and 4,-7

Phoenix [80]

<h3>Answer: (3, -1)</h3>

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

Explanation:

The midpoint formula is $(x_m, y_m) = \left(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2}\right)$

This basically says to add the corresponding coordinates and divide by 2.

The given points (2,5) and (4,-7) have x coordinates of 2 and 4. They add to 2+4 = 6, and then that result cuts in half to 6/2 = 3. The x coordinate of the midpoint is 3.

The y coordinate of the midpoint is y = -1 since adding the y coordinates of the given points leads to 5+(-7) = -2 which cuts in half to -1.

So overall the midpoint is located at (3, -1)

8 0

3 years ago

Roxanne has $20 and she wants to buy some shirts. She picks one shirt that costs $10.99 and two shirts that cost $4.99 each.

timurjin [86]

Answer:

A

Step-by-step explanation:

bc it's the most simple option for roxanne

7 0

3 years ago

Read 2 more answers

What is a radius of a circle given by the equation x²-2x+8y-47=0

Zolol [24]

First, we are going to rewrite it as a parabola equation.
Rewrite.
$8y=-x^2+2x+47$
Divide by 8.
$y=-\frac{x^2}{8}+\frac{x}{4}+\frac{47}{8}$
Factor out coefficient.
$y=-\frac{1}{8}\left(x^2-2x\right)+\frac{47}{8}$
Then, we are going to convert x into square form.
$y=-\frac{1}{8}\left(x^2-2x+1\right)+\frac{1}{8}\cdot \:1+\frac{47}{8}$
Convert the whole expression into square form.
$y=-\frac{1}{8}\left(x-1\right)^2+\frac{1}{8}\cdot \:1+\frac{47}{8}$
Simplify.
$y=-\frac{1}{8}\left(x-1\right)^2+6$
Subtract 6 from both sides.
$y-6=-\frac{1}{8}\left(x-1\right)^2$
Divide by coefficient.
$-8\left(y-6\right)=\left(x-1\right)^2$
Rewrite in standard form.
$4\left(-2\right)\left(y-6\right)=\left(x-1\right)^2$

The radius of the circle will be -2. Also, no matter what the sign says, the radius has to always be positive.
Have a nice day! :)

7 0

3 years ago

Read 2 more answers

(1/2+2/3)÷2 5/6×15-3 1/7​

(1/2+2/3)÷2 5/6×15-3 1/7