Which number is rational? Please help me

The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 246.9 and a standard deviation of 6

belka [17]

Answer:

The approximate percentage of women with platelet counts within 1 standard deviation of the mean, or between 177.6 and 316.2 is 68%.

The approximate percentage of women with platelet counts between 39.0 and 454.8 is 99.7%

Step-by-step explanation:

Mean : $\mu = 246.9$

Standard deviation : $\sigma = 0.49$

Empirical rule :

1 ) 68% of the data lies within 1 standard deviation of mean

This means 68% of data lies between: $\mu-\sigma$ to $\mu+\sigma$

2) 95% of the data lies within 2 standard deviation of mean

This means 95% of data lies between: $\mu-2\sigma$ to $\mu+2\sigma$

3) 99.7% of the data lies within 3 standard deviation of mean

This means 99.7% of data lies between: $\mu-3\sigma$ to $\mu+3\sigma$

Now to find the approximate percentage of women with platelet counts within 1 standard deviation of the mean, or between 177.6 and 316. 2

Use rule 1: $\mu-\sigma$ to $\mu+\sigma$

$246.9-69.3$ to $246.9+69.3$

$177.6$ to $316.2$

So, according to rule 1, 68% of the data lies within 1 standard deviation of mean i.e. 68% of the data lies between 177.6 and 316.2.

Now to find the approximate percentage of women with platelet counts between 39.0 and 454.8?

Use rule 3: $\mu-3\sigma$ to $\mu+3\sigma$

$\mu-3\sigma$ to $\mu+3\sigma$

$39$ to $454.8$

So, According to rule 3 : 99.7% of the data lies within 3 standard deviation of mean i.e. 99.7% of data lies between 39.0 and 454.8

3 0

3 years ago

What is the distance between (-4, 8) and (12, 8) on the coordinate plane? A 16 units B 8 units C 0 units D 4 units

Papessa [141]

Answer:

16 units

Step-by-step explanation:

We need to find the distance between (-4, 8) and (12, 8) on the coordinate plane.

We know that the distance between two points on the coordinate plane is given by :

$D=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Put x₁ = -4, x₂ = 12, y₁ = 8 and y₂ = 8

So,

$D=\sqrt{(12-(-4))^2+(8-8)^2}\\\\=16\ units$

So, the distance between the two points is equal to 16 units.

5 0

2 years ago

Pepper Jackie has 225 square inches for the area for her square mosaic.

Marta_Voda [28]

Answer:

ugh man do I hate iready!!

225/4=56.25

square root of 225 equals 15

225 / 2 equals 112.5

5 0

3 years ago

Which expression is equivalent to 8a + 20?

Darina [25.2K]

To determine the expression that is equivalent to 8a + 20, all you have to do is find the common denominator and divide the values by it.

8a + 20
8a/4 + 20/4
4(2a + 5).

The correct solution would cue the second option - 4(2a + 5).

3 0

3 years ago

Read 2 more answers

The distribution of the number of viewers for the American Idol television show follows a normal distribution with a mean of 26

hjlf

Answer:

Probability that next week's show will have between 30 and 37 million viewers is 0.2248.

Step-by-step explanation:

We are given that the distribution of the number of viewers for the American Idol television show follows a normal distribution with a mean of 26 million with a standard deviation of 8 million.

Let X = number of viewers for the American Idol television show

So, X ~ N( $\mu=26,\sigma^{2}=8^{2}$ )

Now, the z score probability distribution is given by;

Z = $\frac{X-\mu}{\sigma}$ ~ N(0,1)

where, $\mu$ = population mean = 26 million

$\sigma$ = standard deviation = 8 million

So, probability that next week's show will have between 30 and 37 million viewers is given by = P(30 < X < 37) = P(X < 37) - P(X $\leq$ 30)

P(X < 37) = P( $\frac{X-\mu}{\sigma}$ < $\frac{37-26}{8}$ ) = P(Z < 1.38) = 0.91621

P(X $\leq$ 30) = P( $\frac{X-\mu}{\sigma}$ $\leq$ $\frac{30-26}{8}$ ) = P(Z $\leq$ 0.50) = 0.69146

Therefore, P(30 < X < 37) = 0.91621 - 0.69146 = 0.2248

Hence, probability that next week's show will have between 30 and 37 million viewers is 0.2248.

4 0

3 years ago