Which polynomials are in standard form?

An article reported that what airline passengers like to do most on long flights is rest or sleep; in a survey of 3697 passenger

slava [35]

Answer:

Step-by-step explanation:

Hello!

The study variable is:

X: number of passengers that rest or sleep during a flight.

The sample taken is n=9 passengers and the probability of success, that is finding a passenger that either rested or sept during the flight, is p=0.80.

I'll use the binomial tables to calculate each probability, these tables give the values of accumulated probability: P(X≤x)

a. P(6)= P(X=6)

To reach the value of selecting exactly 6 passengers you have to look for the probability accumulated until 6 and subtract the probability accumulated until the previous integer:

P(X=6)= P(X≤6)-P(X≤5)= 0.2618-0.0856= 0.1762

b. P(9)= P(X=9)

To know the probability of selecting exactly 9 passengers that either rested or slept you have to do the following:

P(X≤9) - P(X≤8)= 1 - 0.8657= 0.1343

c. P(X≥6)

To know what percentage of the probability distribution is above six, you have to subtract from the total probability -1- the cumulated probability until 6 but without including it:

P(X≥6)= 1 - P(X<6)= 1 - P(X≤5)= 1 - 0.0856= 0.9144

I hope it helps!

6 0

3 years ago

Working together to palms can drain a certain pool in three hours if it takes the older pump nine hours to drain the pool by its

andreyandreev [35.5K]

Answer:

It would take the newer pump 4.5 hours to drain the pool

Step-by-step explanation:

Let's investigate first what is the fraction of the job done in the unit of time (hour in this case) by each pump if the work individually:

older pump: if it takes it 9 hours to complete the job, it does $\frac{1}{9}$ of the job in one hour.

newer pump: we don't know how long it takes (this is our unknown) so we call it "x hours". Therefore, in the unit of time (in one hour) it would have completed $\frac{1}{x}$ of the total job.

both pumps together: since it takes both 3 hours to complete the job, in one hour they do $\frac{1}{3}$ of the job.

Now, we can write the following equation about fractions of the job done:

The fraction of the job done by the older pump plus the fraction of the job done by the newer pump in one hour should total the fraction of the job done when they work together. That is in mathematical terms:

$\frac{1}{9} +\frac{1}{x} =\frac{1}{3}$