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2 years ago

Urgent please!!! I really don’t understand it, tysm to anyone who can answer thissss :))))

Mathematics

1 answer:

Tomtit [17]2 years ago

3 0

Given:

The frequency distribution table.

To find:

The mean average score on a test.

Solution:

The frequency distribution table is

$Marks (x_i)$ $Frequency(f_i)$ $f_ix_i$

x a xa

y b yb

z c zc

Sum a+b+c xa+yb+zc

Now, the mean average score on the test is

$Mean=\dfrac{\sum f_ix_i}{\sum f_i}$

$Mean=\dfrac{xa+yb+zc}{a+b+c}$

Therefore, the mean average score on the test is $\dfrac{xa+yb+zc}{a+b+c}$ .

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0.3 x 103<br>0 3 x 1025<br>Write the following as an ordinary number. [<br>(1 Point<br>3x10

Ne4ueva [31]

0.3 x 103 = 30.9
0.3 x 1025 = 307.5

3 x 10^5 = 300,000

3 0

2 years ago

Answer the following: a) 2x32 =<br> b) (2 x 3)2 =

wel

Answer:

a) 64 b) 12

Step-by-step explanation:

32 + 32 = 64

2*3 = 6

6*2 = 12

6 0

3 years ago

Read 2 more answers

In Illinois, 9% of all drivers arrested for DUI (Driving Under the Influence) are repeat offenders; that is, they have been arre

Veseljchak [2.6K]

Answer:

a) 21.58% probability that exactly 3 people are repeat offenders

b) 97.91% probability that at least one person is a repeat offender

c) 3.69

d) 1.83

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

9% of all drivers arrested for DUI (Driving Under the Influence) are repeat offenders

This means that $p = 0.09$

41 people arrested for DUI in Illinois are selected at random.

This means that $n = 41$

a. What is the probability that exactly 3 people are repeat offenders?

This is P(X = 3).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{41,3}.(0.09)^{3}.(0.91)^{38} = 0.2158$

21.58% probability that exactly 3 people are repeat offenders

b. What is the probability that at least one person is a repeat offender?

Either none are repeat offenders, or at least one is. The sum of the probabilities of these outcomes is 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ .

Then

$P(X \geq 1) = 1 - P(X = 0)$

In which

$P(X = 0) = C_{41,0}.(0.09)^{0}.(0.91)^{41} = 0.0209$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0209 = 0.9791$

97.91% probability that at least one person is a repeat offender

c. What is the mean number of repeat offenders?

$E(X) = np = 41*0.09 = 3.69$

d. What is the standard deviation of the number of repeat offenders?

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{41*0.09*0.91} = 1.83$

4 0

2 years ago

Hey anyone know this ?

Sergeu [11.5K]

Answer:

It's an equilateral triangle so the measure of each angle here=60 degrees

s..4x degree=15*4

hence, the value of X=15

<h2>Have a good day Ahead:)</h2>

6 0

3 years ago

Helppppppppp plzzzzz

Shkiper50 [21]

Answer: 4

Step-by-step explanation:

so you basically make the + sign into a - sign as when there is a + and - sign next to each other it will always change into a - sign so once you do that it will look like this

11+(-7)

11-7

8 0

3 years ago