A math question about proportions, help

The number of siblings an individual has varies from student to student. The distribution of the number of siblings is strongly

ivanzaharov [21]

Answer:

(e) the mean number of siblings for a large number of students has a distribution that is close to Normal.

Step-by-step explanation:

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 $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

By the Central Limit Theorem

The sampling distributions with a large number of students(at least 30) will be approximately normal, so the correct answer is given by option e.

7 0

3 years ago

Gỉa sử GDP là 8000$, thuế là 1500$, tiết kiệm tư nhân là 500$, tiết kiệm chính phủ là 200$. Gỉa sử đây là nền kinh tế đóng. Tính

kodGreya [7K]

i dont understand pls tell me in english

4 0

3 years ago

A scale drawing has a scale of 3 in. . 1 ft. What is the scale factor?

Alex17521 [72]

The scale factor of that problem would be 3in to every 1ft

3 0

3 years ago

Read 2 more answers

A motorboat travels 168 kilometers in 4 hours going upstream. It travels 280 kilometers going downstream in the same amount of t

Grace [21]

Answer:

The speed of the boat is 56 km/hr

The rate of the current is 14 km/hr

Step-by-step explanation:

We are given the following;

Distance traveled upstream = 168 km
Time taken to travel upstream = 4 hours
Distance traveled down stream = 280 km
Time taken down stream = 4 hours

We are required to determine the speed of the boat in still water and the speed of the current.

We are going to take;

Speed of the boat as = x km/hr

Rate of flow of current = y km/hr

We can determine the speed of the boat upstream;

Speed = Distance ÷ time

= 168 km ÷ 4 hours

= 42 km/hr

But, the speed upstream is given by (x - y) km/hr

Therefore; ( x-y) km/hr = 42 km/hr ......................... Eqn 1

Speed of the boat down stream

speed = 280 km ÷ 4 hours

= 70 km/hr

But, the speed downstream is given by (x+y) km/hr

Therefore, x+y km/hr = 70 km/hr ........................... Eqn 2

Solving Eqn 1 and Eqn 2 simultaneously;

x - y = 42

x + y = 70

Eliminating x

-2y = - 28

y = 14 km/hr

Solving for x,

x = 42 + y

= 42 + 14

= 56 km/hr

Therefore, the speed of the boat is 56 km/hr while the rate of the current is 14 km/hr

8 0

4 years ago

What is the probability of rolling a sum of 5 on a standard pair of six-sided dice? express your answer as a fraction or a decim

viva [34]

The probability of rolling a sum of 5 on a standard pair of six sided dice is 1/9.

According to the given question.

A standard pair of dice is rolled.

So, the sample sapce for rolling a pair of dice = {(1,1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (5, 1), (5, 2), (5, 3), (5, 4),(5, 5),(5, 6), (6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)}

⇒ Total number of outcomes = 36

And, the outcomes for getting a sum of five on a sandard pair of six sided dice = {(2, 3), (3, 2), (4, 1), (1, 4)}

⇒ Total number of favorable outcomes = 4

As we know that " probability is the ratio of total number of favorable outcomes to the total number of outcomes".

Therefore,

The probability of rolling a sum of 5 on a standard pair of six-sided dice

= 4/36

= 1/9

Hence, the probability of rolling a sum of 5 on a standard pair of six sided dice is 1/9.

Find out more information about probability here:

brainly.com/question/11234923

#SPJ4

8 0

2 years ago