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4 years ago

In Mr. Diaz’s class, 20% of the students received a grade of “A” on their report cards. There are 25 students in

Mathematics

2 answers:

Simora [160]4 years ago

7 0

25/x=100/20 criss cross and u will get 500/100=5 then 5 students resivs A.

alexandr1967 [171]4 years ago

7 0

Im not sure but I think 5 because there are 25 students so put 25 in the denominator Set up a proportion Put 20 over 100 because percent means something over 100 25 times 4 is 100 20 divided by 4 is 5 So the answer is 5

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3 years ago

An airline allows each passenger to have a suitcase weighing no more than 45 lbs. If Hank needs to lower his suitcase weight by

diamong [38]

Okay, so he started out with 45 lbs.

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3 years ago

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2 years ago

Write the slope-intercept form of the equation of the line that passes thrqugh (-4, -3) and is

Zielflug [23.3K]

Answer:

Step-by-step explanation:

Equation of the line y = mx + c

The new line is perpendicular to 2x - 3y = -5

- 3y = - 5 - 2x

3y = 2x + 5

y = $\frac{2x}{3} + \frac{5}{3}$

Since the lines are perpendicular to each other : $m_{1} . m_{2} = -1$

where $m_{1} \ slope \ of \ the \ given \ line \ and \ m_{2} \ slope \ of \ the \ new \line\\$ .

Slope of the given line

$m_{1} = \frac{2}{3}$

Slope of the new line

$\\\frac{2}{3}.m_{2} = -1\\ m_{2} = -1 . \frac{3}{2} = \frac{-3}{2}$

The equation to the new line passing through (-4, -3) and perpendicular to 2x - 3y = -5

$(y - y_{1}) = m_{2}(x-x_{2} )\\\\(y - (-4)) = \frac{-3}{2}(x - (-3)) \\\\(y + 4) = \frac{-3}{2} (x+ 3)\\\\2(y +4) = -3(x+3)\\\\2y + 8 = -3x -9 \\\\2y = -3x - 9 -8\\\\y = \frac{-3x}{2} - \frac{17}{2}$

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3 years ago

The Magazine Mass Marketing Company has received 1515 entries in its latest sweepstakes. They know that the probability of recei

wariber [46]

Answer:

$P(x < 5)=P(X=0)+P(X=1)+P(X=2)+P(x=3)+P(X=4)$

$P(X=0)=(15C0)(0.5)^0 (1-0.5)^{15-0}=0.0000305$

$P(X=1)=(15C1)(0.5)^1 (1-0.5)^{15-1}=0.000458$

$P(X=2)=(15C2)(0.5)^2 (1-0.5)^{15-2}=0.0032$

$P(X=3)=(15C3)(0.5)^3 (1-0.5)^{15-3}=0.0139$

$P(X=4)=(15C4)(0.5)^4 (1-0.5)^{15-4}=0.0417$

And adding we got:

$P(x < 5)=0.0592$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=15, p=0.5)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

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

And we want to find this probability:

$P(x < 5)=P(X=0)+P(X=1)+P(X=2)+P(x=3)+P(X=4)$

$P(X=0)=(15C0)(0.5)^0 (1-0.5)^{15-0}=0.0000305$

$P(X=1)=(15C1)(0.5)^1 (1-0.5)^{15-1}=0.000458$

$P(X=2)=(15C2)(0.5)^2 (1-0.5)^{15-2}=0.0032$

$P(X=3)=(15C3)(0.5)^3 (1-0.5)^{15-3}=0.0139$

$P(X=4)=(15C4)(0.5)^4 (1-0.5)^{15-4}=0.0417$

And adding we got:

$P(x < 5)=0.0592$

7 0

3 years ago