I NEED HELP PLSSSSSSSSSSS

Molodets [167]

A is more because 1/4 is equal to 2/8 and 2/8 is less than 7/8 so you would have more than a minute
B is three minutes 2/8 goes into 7/8 three times

8 0

3 years ago

In the given figure p=120° and y : z=2 : 3 Find x, y and z

Sindrei [870]

Answer:

x = 60°

y = 72°

z = 48°

Step-by-step explanation:

x = 180 - p = 180 - 120 = 60

Since y;z = 3:2 , 2y = 3z or z = 2y/3

Now, x + y + z = 180

60 + y + 2y/3 = 180 Multiply thru by 3 to remove the fraction

180 + 3y + 2y = 540

180 + 5y = 540

5y = 360

y = 72

z = 2(72)/3 = 48

Check: 60 + 72 + 48 = 180

5 0

3 years ago

An integer from 300 through 780, inclusive is to be chosen at random, find the probability that the number is chosen will have 1

exis [7]

Answer:

93/481

Step-by-step explanation:

Total number of integers from 300 through 780, inclusive:

780 - 299 = 481

Number of integers with at least one of digit 1:

Hundreds - 0,
Tens - 5*10 = 50 (31th, 41th, 51th, 61th, 71th)
Units - 4*9 + 7 = 43 (300 till 699 and 700 till 780)
So in total 50 + 43 = 93

The probability is:

P = favorable outcomes/total outcomes = 93/481

6 0

3 years ago

A practice law exam has 100 questions, each with 5 possible choices. A student took the exam and received 13 out of 100.If the s

Cloud [144]

Answer:

$z=\frac{13-20}{4}=-1.75$

Assuming:

H0: $\mu \geq 20$

H1: $\mu$

$p_v = P(Z$

Step-by-step explanation:

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".

Let X the random variable of interest (number of correct answers in the test), on this case we now that:

$X \sim Binom(n=100, p=0.2)$

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:

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

We need to check the conditions in order to use the normal approximation.

$np=100*0.2=20 \geq 10$

$n(1-p)=20*(1-0.2)=16 \geq 10$

So we see that we satisfy the conditions and then we can apply the approximation.

If we appply the approximation the new mean and standard deviation are:

$E(X)=np=100*0.2=20$

$\sigma=\sqrt{np(1-p)}=\sqrt{100*0.2(1-0.2)}=4$

So we can approximate the random variable X like this:

$X\sim N(\mu =20, \sigma=4)$

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean". The letter $\phi(b)$ is used to denote the cumulative area for a b quantile on the normal standard distribution, or in other words: $\phi(b)=P(z$