Can someone help me fully simplify this step by step pleaseeeee

In brianna's homeroom class, 9% of the students were born in march and 40% of the students have a blood type of o+.

Firlakuza [10]

Answer:

3.6%

Step-by-step explanation:

Because the two events are independent, their probabilities are multiplied, so the probability of a student being born in March and having a blood type of O+ is 9% * 40% = 0.09 * 0.40 = 0.036 = 3.6%

3 0

2 years ago

Assume that population mean is to be estimated from the sample described. Use the sample results to approximate the margin of er

Vikentia [17]

Answer:

$ME=1.998 \frac{4}{\sqrt{64}}=0.999 \approx 1$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X =69$ represent the sample mean for the sample

$\mu$ population mean

s=4.0 represent the sample standard deviation

n=64 represent the sample size

Assuming the X follows a normal distribution

$X \sim N(\mu, \sigma)$

The sample mean $\bar X$ have the following distribution:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

The margin of error for the sample mean is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

Since we have the sample standard deviation we can estimate the margin of error like this:

$ME=t_{\alpha/2}\frac{s}{\sqrt{n}}$

The next step would be find the value of $\z_{\alpha/2}$ , $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$

We can find the degrees of freedom like this:

$df=n-1=64-1=63$

And we can find the critical value with the following code in excel for example: "=T.INV(0.025,63)" and we got:

$t_{\alpha/2}=\pm 1.998$

And the margin of error would be :

$ME=1.998 \frac{4}{\sqrt{64}}=0.999 \approx 1$

3 0

3 years ago

Explain how you know whether to add or subtract when you use the distributive property to multiply

MissTica

If you use a distributive or multiply is all kind a same

7 0

3 years ago

What is the formula to find the area of a triangle? choose all that apply

Nana76 [90]

Answer:

the second and thrid one :)

Step-by-step explanation:

3 0

3 years ago

Arthur weighs 34 lb more than Lily. Their combined weight is 180 lbs less than four times Lily's weight. How much does Arthur we

mote1985 [20]

X = Lilys weight
x + 34 = Arthurs weight
4x - 180 = combined weight

x + x + 34 = 4x = 180
2x + 34 = 4x - 180
-2x -2x
_________________
34 = 2x -180
+180 + 180
_______________
214 = 2x
107 = x which is Lily's weight
141 = x + 34 which is Arthur's weight
The total weight is 248

which is the answer that you get when you do 4(107) = 180 or
428 -180 = 248

5 0

3 years ago