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3 years ago

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Joe takes part in math competitions. A particular contest consists of 25 multiple-choice questions, and each question has 5 poss

ible answers. It awards 6 points for each correct answer, 1.5 points for each answer left blank, and 0 points for incorrect answers. Joe is sure of 12 of his answers. He ruled out 2 choices before guessing on 4 of the other questions and randomly guessed on the 9 remaining problems. What is his expected score?
69.2
75.6
90.8
97.2

2 answers:

motikmotik3 years ago

7 0

<h2>C. 90.8 </h2>

Is the correct answer.

Hope I helped!

Romashka-Z-Leto [24]3 years ago

5 0

your answer is C.

HOPE THIS HELPS!!

PLEASE MARK ME AS BRAINLIEST!!

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Will mark brainliest !!

ikadub [295]

Given Fig.is a triangle

Perimeter is simply sum of the all sides of a triangle

1/3x + 7/x^2 + (x+2)/x

=[ x+ 21 + 3x(x+2)]/3x^2

= (x+ 21 + 3x^2 + 6x)/3x^2

= (3x^2 + 7x +21)/3x^2

7 0

3 years ago

Read 2 more answers

A certain disease occurs most frequently among older women. Of all age groups, women in their 60s have the highest rate of breas

Law Incorporation [45]

Answer:

The probability that a woman in her 60s has breast cancer given that she gets a positive mammogram is 0.0276.

Step-by-step explanation:

Let a set be events that have occurred be denoted as:

S = {A₁, A₂, A₃,..., Aₙ}

The Bayes' theorem states that the conditional probability of an event, say <em>A</em>ₙ given that another event, say <em>X</em> has already occurred is given by:

$P(A_{n}|X)=\frac{P(X|A_{n})P(A_{n})}{\sum\limits^{n}_{i=1}{P(X|A_{i})P(A_{i})}}$

The disease Breast cancer is being studied among women of age 60s.

Denote the events as follows:

<em>B</em> = a women in their 60s has breast cancer

+ = the mammograms detects the breast cancer

The information provided is:

$P(B) = 0.0312\\P(+|B)=0.81\\P(+|B^{c})=0.92$

Compute the value of P (B|+) using the Bayes' theorem as follows:

$P(B|+)=\frac{P(+|B)P(B)}{P(+|B)P(B)+P(+|B^{c})P(B^{c})}$

$=\frac{(0.81\times 0.0312)}{(0.81\times 0.0312)+(0.92\times (1-0.0312)}\\$

$=\frac{0.025272}{0.025272+0.891296}$

$=0.02757\\\approx0.0276$

Thus, the probability that a woman in her 60s has breast cancer given that she gets a positive mammogram is 0.0276.

4 0

3 years ago

Read 2 more answers

The table below represents a function. Which of the following equations could be its function rule?

worty [1.4K]

Answer:

$y=2x-2$ is the required equation.

Therefore, the second option is true.

Step-by-step explanation:

We know that the slope-intercept form of the line equation of a linear function is given by

$y=mx+b$

where m is the slope and b is the y-intercept

Taking two points (0, -2) and (1, 0) from the table to determine the slope using the formula

$\mathrm{Slope}=\frac{y_2-y_1}{x_2-x_1}$

$\left(x_1,\:y_1\right)=\left(0,\:-2\right),\:\left(x_2,\:y_2\right)=\left(1,\:0\right)$

$m=\frac{0-\left(-2\right)}{1-0}$

$m=2$

substituting the point (0, -2) and the slope m=2 in the slope-intercept form to determine the y-intercept i.e. 'b'.

$y=mx+b$

$-2 = 2(0)+b$

$-2=0+b$

$b=-2$

Now, substituting the values of m=2 and b=-2 in the slope-intercept form to determine the equation of a linear function

$y=mx+b$

$y=2x+(-2)$

$y=2x-2$

Thus, $y=2x-2$ is the required equation.

Therefore, the second option is true.

3 0

3 years ago

14 POINTS for solving x in 14 Angle Relationships problems

ipn [44]

Answer:

x= 14

x=66,000

x=12.7

x=34^2

Step-by-step explanation:

5 0

3 years ago

X2 + 45x = -200 Using the quadratic formual and the discirimnat

dybincka [34]

Answer:

Positive discriminant = 2 real solution

x= -5,-40

Step-by-step explanation:

The discriminant is used to see how many solutions an equation has. If it is negative, the equation has no real solutions, if =0 the equation has 1, and if it is positive, the equation has two real solutions.

The discriminant is the part of the quadratic formula inside the square root:

$b^{2}-4ac$

Every quadratic formula has the structure:

$ax^{2} +bx+c=0$

So first, in order to meet this structure we need to add 200 to both sides so the equation is equal to 0. This gives us:

$x^{2} +45x+200=0$

Our a=1, b=45 and c=200

Now we can substitute these values into the discriminant:

$(45)^{2} -4(1)(200)$

Solve:

$2025-800=1225$

The discriminant is a positive number which means this equation will have 2 real solution. Now we just need to plug in our values into the quadratic formula to solve this equation. Quadratic formula:

$x=\frac{-+/-\sqrt{b^{2}-4ac} }{2a} \\x=\frac{-45+/-\sqrt{1225} }{2}$

(Same discriminant value)

$x=\frac{-45+/-35}{2}$

Now to find the two solutions, we use both signs in the equation. Solution 1:

$x=\frac{-45+35}{2}$

$x=\frac{-10}{2}=-5$

Our first solution is -5, now for the second:

$x=\frac{-45-35}{2}\\\\ x=\frac{-80}{2}=-40$

The two solution to this equation are -5 and -40.

Hope this helped!

7 0

3 years ago