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3 years ago

8

Marques earned a grade of 54% on his multiple choice math final that had a total of 200 problems. How many problems on the final

exam did Marques answer correctly?

1 answer:

seraphim [82]3 years ago

8 0

Answer:

108

Step-by-step explanation:

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A couple book a cruise to Alaska that promises to refund 100 per day of rain on the seven day cruise up to a maximum of 300. The

zubka84 [21]

Answer:

the variance of the refund payment to the couple = 9463.394

Step-by-step explanation:

Given that :

A couple book a cruise to Alaska that promises to refund 100 per day of rain on the seven day cruise up to a maximum of 300.

It is possible that the couple won't be able to refund up 100 per day or more than 100 per day.

SO; let assume that the refund payment happens to be 0, 100,200, 300

Let X be the total refund payment on the seven day cruise.

We can say X = 0, if there is no rain on all 7 days.

$P(X = 0) = _nC_x * P^x * (1 - P)n-x$

$P(X = 0) = _7C_o * 0.2^0 * (1-0.2)^{7-0$

$P(X = 0) =1 * 1* (1-0.2)^{7$

$P(X = 0) =(0.8)^{7$

$P(X = 0) =0.2097152$

If it rains on any one day; then X = 100

$P(X = 100) = _nC_x * P^x * (1 - P)n-x$

$P(X = 100) = _7C_1 * 0.2^1 * (1-0.2)^{7-1$

$P(X = 0) =7 * 0.2* (1-0.2)^{6$

$P(X = 100) =7* 0.2* (0.8)^{6$

$P(X = 100) =0.3670016$

if it rains on any two day ; then X = 200

$P(X = 200) = _nC_x * P^x * (1 - P)n-x$

$P(X = 200) = _7C_2 * 0.2^2 * (1-0.2)^{7-2$

$P(X = 200) = 21 * 0.2^2 * (0.8)^{5$

$P(X = 200) = 0.2752512$

if it rains on any three day or more than that ; then X = 300

$P(X \ge 300) = 1 - P(X < 300) \\ \\ P(X \ge 300) = 1 - [P(X = 0) + P(X = 100) + P(X = 200)] \\ \\ P(X \ge 300) = 1 - [0.2097152 + 0.3670016 + 0.2752512] \\ \\ P(X \ge 300) = 0.148032$

Now; we have our probability distribution function as:

P(X = 0) = 0.2097152

P(X = 100) = 0.3670016

P(X = 200) = 0.2752512

P(X = 300) = 0.148032

In order to determine the variance of the refund payment to the couple; we use the formula:

variance of the refund payment to the couple $[Var X] =E [X^2] - (E [X])^2$

where;

$E[X^2] = \sum x^2 \times p \\ \\ E[X^2] = 0^2 * 0.2097152 + 100^2 * 0.3670016 + 200^2 * 0.2752512 + 300^2 * 0.148032 \\ \\ E[X^2] = 0 + 3670.016 + 11010.048+ 13322.88 \\ \\ E[X^2] =28002.944$

$(E [X]) = \sum x * p\\ \\ (E [X]) = 0 * 0.2097152 + 100 * 0.3670016 + 200 * 0.2752512 + 300 * 0.148032 \\ \\ (E [X]) = 0 + 36.70016 + 55.05024 + 44.4096\\ \\ (E [X]) = 136.16 \\ \\ (E [X])^2 = 136.16^2 \\ \\ (E [X])^2 = 18539.55$

NOW;

the variance of the refund payment to the couple = 28002.944 - 18539.55

the variance of the refund payment to the couple = 9463.394

7 0

3 years ago

How many permutations are there of the letters in the word surprise?

azamat

Surprise, there 8 letters.
So, 8*7*6*5*4*3*2*1= 40, 320

5 0

3 years ago

How do you solve this 8*[[(7+4)*2]-[(11-7)*4]]? I am trying to help my son with his homework and sad to say I am 46 and I can't

elena55 [62]

Answer: 160

Step-by-step explanation:

Don't know how to

7 0

3 years ago

Isaiah has $7.15 in Dimes and Nickels. He has a total of 91 coins. How many of each coin does he have? Group of answer choices d

yarga [219]

Answer:

Dimes = x = 52

Nickels = y = 39

Step-by-step explanation:

Let

Dimes = x

Nickels = y

x + y = 91 (1)

0.10x + 0.05y = 7.15 (2)

From (1)

x = 91 - y

Substitute x = 91 - y into (2)

0.10x + 0.05y = 7.15

0.10(91 - y) + 0.05y = 7.15

9.10 - 0.10y + 0.05y = 7.15

- 0.10y + 0.05y = 7.15 - 9.10

-0.05y = -1.95

y = -1.95 / 0.05

= 39

Substitute y = 39 into (1)

x + y = 91

x + 39 = 91

x = 91 - 39

x = 52

Dimes = x = 52

Nickels = y = 39

7 0

3 years ago

grandymaker [24]

Answer:

see attached

angles: 39.8°, 68.2°; side: 8

Step-by-step explanation:

The triangle and its measurements are shown in the attachment.

_____

If you do this with pencil and paper and protractor, likely your angle measurements will only be to the nearest degree.

8 0

4 years ago