The difference of two numbers is 18, and their sum is 90. Find the number

Please help I need some guidance.

Rzqust [24]

Answer:

1/333 is answer........

5 0

2 years ago

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3x=15-6y in slope intercept form

sdas [7]

Answer: y= -1/2x + 5/2

Step-by-step explanation:

3x = 15 -6y

+6y + 6y

3x +6y =15

-3x -3x

6y= 15-3x divide both sides by 6

y= 15/6 - 3/6x

in slope intercept form us y= -3/6x + 15/6 in simplest form is y= -1/2x + 5/2

3 0

3 years ago

Suppose that prior to conducting a coin-flipping experiment, we suspect that the coin is fair. How many times would we have to f

BabaBlast [244]

Answer:

153 times

Step-by-step explanation:

We have to flip the coin in order to obtain a 95.8% confidence interval of width of at most .14

Width = 0.14

ME = $\frac{width}{2}$

ME = $\frac{0.14}{2}$

ME = $0.07$

$ME\geq z \times \sqrt{\frac{\widecap{p}(1-\widecap{p})}{n}}$

use p = 0.5

z at 95.8% is 1.727(using calculator)

$0.07 \geq 1.727 \times \sqrt{\frac{0.5(1-0.5)}{n}}$

$\frac{0.07}{1.727}\geq sqrt{\frac{0.5(1-0.5)}{n}}$

$(\frac{0.07}{1.727})^2 \geq \frac{0.5(1-0.5)}{n}$

$n \geq \frac{0.5(1-0.5)}{(\frac{0.07}{1.727})^2}$

$n \geq 152.169$

So, Option B is true

Hence we have to flip 153 times the coin in order to obtain a 95.8% confidence interval of width of at most .14 for the probability of flipping a head

6 0

3 years ago

The probability that a grader will make a marking error on any particular question of a multiple-choice exam is 0.15. If there a

sashaice [31]

Answer:

$P(X=0)=(10C10)(0.15)^{0} (1-0.15)^{10-0}=0.1969$

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

$P(X=0)=(nCn)(p)^{0} (1-p)^{n-0}=(1-p)^n$

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

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

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".

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:

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

The complement rule is a theorem that provides a connection between the probability of an event and the probability of the complement of the event. Lat A the event of interest and A' the complement. The rule is defined by: $P(A)+P(A') =1$

Solution to the problem

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

$X \sim Binom(n=10, p=0.15)$

what is the probability that no errors are made?

For this case means that all the questions were correct so we want this probability:

$P(X=0)=(10C10)(0.15)^{0} (1-0.15)^{10-0}=0.1969$

what is the probability that at least one error made?

For this case we want this probability:

$P(X \geq 1)$

And we can use the complement rule:

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

If there are n questions and the probability of a marking error is p rather than 0.15, give expressions for the probabilities of no errors and at least one error

$P(X=0)=(nCn)(p)^{0} (1-p)^{n-0}=(1-p)^n$

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

8 0

3 years ago

(1CQ) Write the repeating decimal as a fraction .51

egoroff_w [7]

Answer: Your answer is 17/33! Hope this helps. If you need anymore help let me know!

8 0

3 years ago

Read 2 more answers

The difference of two numbers is 18, and their sum is 90. Find the number​

The difference of two numbers is 18, and their sum is 90. Find the number