Points A and B lie on a circle centered at point O. If what is the ratio of the area of sector AOB to the area of the circle?

STatiana [176]

If angleb is 120 then AC is 120*2 = 240. 360-240 = 120 , 120/2 = 60 . If AB = 60 , angle adb is 30 and angle bdc is 30. DB is 2 * radius because angleA is 90. So with Pisagor AB = 3 , BC = 3 , AD = 3root3 and DC is 3root3.

Answer is = 6+6root3 = 6(1 + root3)

7 0

3 years ago

Use the substitution method to solve the system of equations. Choose the correct ordered pair.

Gnom [1K]

Answer:

i would say b

Step-by-step explanation:

6 0

3 years ago

A charity receives 2025 contributions. Contributions are assumed to be mutually independent and identically distributed with mea

uysha [10]

Answer:

The 90th percentile for the distribution of the total contributions is $6,342,525.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

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

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .