Event A: Flipping heads on a coin.Event B: Spinning orange on the spinner shown (4 parts to the spinner) .What is P(A and B)?

A teacher gives a test to a large group of students. The results are closely approximated by a normal curve. Teh mean is 73, wit

zavuch27 [327]

Answer:

The bottom for an A is 75. Round to the nearest whole number as needed.

Step-by-step explanation:

1) Previous concepts

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".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Let X the random variable that represent the scores on this case, and for this case we know the distribution for X is given by:

$X \sim N(\mu=73,\sigma=7)$

And let $\bar X$ represent the sample mean, the distribution for the sample mean is given by:

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

2) The bottom for an A is _____. Round to the nearest whole number as needed.

And we want the top 5.5% of the scores, so we need a value a such that:

$P(X>a)=0.055$ or $P(X$

We need on the right tail of the distribution a value a that gives to us 94.5% of the area below and 5.5% of the area above. Both conditions are equivalent.

Let's use the condition $P(X$ , the best way to solve this problem is using the z score with the following formula:

$z=\frac{x-\mu}{\sigma}$

So we need a value from the normal standard distribution that accumulates 0.945 of the area on the left and 0.055 on the right. This value on this case is 1.598 and we can founded with the following code in excel:

"=NORM.INV(0.945,0,1)"

If we apply the z score formula to our case we have this:

$P(X$

So then based on the equalities we have this:

$\frac{a-73}{7}=1.598$

And if we solve for a we got:

$a=(7*1.598) +73=84.186$

So then we need a score of 84.186 rounded to the nearest whole number 75 or higher in order to get an A

8 0

3 years ago

The table shows the time a patient spends at the dentist and the amount of the bill. A 2-column table with 4 rows. The first col

Vinvika [58]

The correlation coefficient for the data in the table was found to be 0.93.

The correct option is A.

<h3>What is the correlation coefficient?</h3>

The correlation coefficient focuses on the linear relationship between two variables.

Given

The first column is labeled time spent at the dentist (in hours) with entries 1.4, 2.7, 0.75, 1.6.

The second column is labeled bill amount (in dollars) with entries 235, 867, 156, 215.

The numbers between -1 and 1 should be one of the values related to the bill.

Taking the independent variable or input variable as, the time a patient spends at the dentist and the dependent variable or output variable as the amount of the bill.

Hence, The correlation coefficient for the data in the table was found to be 0.93.

To know more about correlation coefficient click the link given below.

brainly.com/question/26197675

3 0

2 years ago

What is the balance after 15 years in a savings account that earns 2% interest compounded bimonthly when the initial deposit is

Ierofanga [76]

Answer:

$1348.07

Step-by-step explanation:

Hello!

<h3>Compound Interest Formula: $A = P(1 + \frac rn)^{nt}$ </h3>

A = Account Balance
P = Principle/Initial Amount
r = Rate of Interest (decimal)
n = Number of times compounded (per year)
t = Number of Years

<h3>Given Information</h3>

Account Balance = ?
Principle Amount = $1000
Rate of Interest = 0.02

Why is the Rate 0.02?

This is because we are gaining money, so the multiplier should be greater than 1. We already added 1, which is 100% so you simply add the 0.02 for the extra 2%.