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3 years ago

5

Consider the following frequency table representing the scores on a test.

1 answer:

larisa [96]3 years ago

5 0

Answer:

(a)56

(b)47

(c)3

(d)29

Step-by-step explanation:

From the given frequency

(a) Fifth class is 56-59.

The lower class boundary for the fifth class is 56.

(b) Second class is 44-47.

The upper-class boundary for the second class is 47.

(c) Class width = 47-44 = 3, 47-44 = 3.

(d) Number of scores between 39.5 and 55.5 is

=7 + 7+ 7 + 8 =29

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A random variableX= {0, 1, 2, 3, ...} has cumulative distribution function.a) Calculate the probability that 3 ≤X≤ 5.b) Find the

olchik [2.2K]

Answer:

a) P ( 3 ≤X≤ 5 ) = 0.02619

b) E(X) = 1

Step-by-step explanation:

Given:

- The CDF of a random variable X = { 0 , 1 , 2 , 3 , .... } is given as:

$F(X) = P ( X =< x) = 1 - \frac{1}{(x+1)*(x+2)}$

Find:

a.Calculate the probability that 3 ≤X≤ 5

b) Find the expected value of X, E(X), using the fact that. (Hint: You will have to evaluate an infinite sum, but that will be easy to do if you notice that

Solution:

- The CDF gives the probability of (X < x) for any value of x. So to compute the P ( 3 ≤X≤ 5 ) we will set the limits.

$F(X) = P ( 3=$

- The Expected Value can be determined by sum to infinity of CDF:

E(X) = Σ ( 1 - F(X) )

$E(X) = \frac{1}{(x+1)*(x+2)} = \frac{1}{(x+1)} - \frac{1}{(x+2)} \\\\= \frac{1}{(1)} - \frac{1}{(2)}\\\\= \frac{1}{(2)} - \frac{1}{(3)} \\\\= \frac{1}{(3)} - \frac{1}{(4)}\\\\= ............................................\\\\= \frac{1}{(n)} - \frac{1}{(n+1)}\\\\= \frac{1}{(n+1)} - \frac{1}{(n+ 2)}$

E(X) = Limit n->∞ [1 - 1 / ( n + 2 ) ]

E(X) = 1

8 0

3 years ago

Joshua sponsored a fundraiser that 708 people attended. He raised $8,640. He charged $15 for balcony seats and $10 for ground se

lozanna [386]

312 people bought balcony seats and 396 people bought ground seats.

5 0

3 years ago

What is the answer for this

Georgia [21]

The domain is all real numbers

5 0

3 years ago

A prince picked a basketful of golden apples in the enchanted orchard. On his way home, he was stopped by a troll who guarded. T

Lelu [443]

Answer:

Let x = total number of apples picked by the prince

x=44

Step-by-step explanation:

1st troll payment

x-(0.5x+2)

x-0.5x-2

0.5x-2 (that is the amount of apples left after 1st troll payment)

2nd troll payment

(0.5x-2)-(0.5(0.5x-2)+2)

Simplifying,

(0.5x-2)-(0.25x-1+2)

(0.5x-2)-(0.25x+1)

0.5x-2-0.25x-1

0.25x-3 (apples remaining after 2nd troll payment)

3rd troll payment

(0.25x-3)-(0.5(0.25x-3)+2)=2

(0.25x-3)-(0.125x-1.5+2)=2

(0.25x-3)-(0.125x+0.5)=2

0.25x-3- 0.125x-0.5=2

0.125x-3.5=2

0.125x =2+3.5

0.125x=5.5

x=5.5/0.125 (divide both sides by 0.125)

=44 apples

Therefore total number of apples picked by the prince, x=44

3 0

4 years ago

Read 2 more answers

what is the common ratio for the geometric sequence below, written as a fraction? 768, 480, 300, 187.5, …

Crazy boy [7]

Let

$a1=768\\a2=480\\a3=300\\a4=187.5$

Step $1$

Find $\frac{a2}{a1}$

$\frac{a2}{a1} =\frac{480}{768}$

Divide by $96$ numerator and denominator

$\frac{480}{768} =\frac{\frac{480}{96}}{\frac{768}{96}} \\ \\ \frac{480}{768}=\frac{5}{8}$

$a2=a1*\frac{5}{8}$

Step $2$

Find $\frac{a3}{a2}$

$\frac{a3}{a2} =\frac{300}{480}$

Divide by $60$ numerator and denominator

$\frac{300}{480} =\frac{\frac{300}{60}}{\frac{480}{60}} \\ \\ \frac{300}{480}=\frac{5}{8}$

$a3=a2*\frac{5}{8}$

Step $3$

Find $\frac{a4}{a3}$

$a4=187.5 \\ a4=187\frac{1}{2} \\ \\ a4=\frac{375}{2}$

$\frac{a4}{a3} =\frac{\frac{375}{2}}{300} \\ \\ \frac{a4}{a3} =\frac{375}{600}$

Divide by $75$ numerator and denominator

$\frac{375}{600} =\frac{\frac{375}{75}}{\frac{600}{75}} \\ \\ \frac{375}{600}=\frac{5}{8}$

$a4=a3*\frac{5}{8}$

In this problem

The geometric sequence formula is equal to

$a(n+1)=a(n)*\frac{5}{8}\\$

For $n\geq 1$

therefore

the answer is

the common ratio for the geometric sequence above is $\frac{5}{8}$

6 0

4 years ago

Read 2 more answers