Please help woth this

1. Marcus needs to bike at least 80 miles this

KonstantinChe [14]

He should ride 11 miles on each of the other 5 days. 11 times 5 equals 55 + 25 = 80.

3 0

3 years ago

Tennis Replay In the year that this exercise was written, there were 879 challenges made to referee calls in professional tennis

tiny-mole [99]

Answer:

a. 0.0209 = 2.09% probability that among the 879 challenges, the number of overturned calls is exactly 231.

b. 231 is less than 2.5 standard deviations above the mean, which means that 231 overturned calls among 879 challenges is not a significantly high result.

Step-by-step explanation:

For each challenge, there are only two possible outcomes. Either it was overturned, or it was not. The probability of a challenge being overturned is independent of any other challenge. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

Significantly high:

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

If a value is more than 2.5 standard deviations above the mean, this value is considered significantly high.

25% of the challenges are successfully upheld with the call overturned.

This means that $p = 0.25$

879 challenges

This meas that $n = 879$

a. If the 25% rate is correct, find the probability that among the 879 challenges, the number of overturned calls is exactly 231.

This is P(X = 231). So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 231) = C_{879,231}.(0.25)^{231}.(0.75)^{648} = 0.0209$

0.0209 = 2.09% probability that among the 879 challenges, the number of overturned calls is exactly 231.

b. If the 25% rate is correct, find the probability that among the 879 challenges, the number of overturned calls is 231 or more. If the 25% rate is correct, is 231 overturned calls among 879 challenges a result that is significantly high

The mean is:

$E(X) = np = 879*0.25 = 219.75$

The standard deviation is:

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{879*0.25*0.75} = 12.84$

$219.75 + 2.5*12.84 = 251.85 > 231$

231 is less than 2.5 standard deviations above the mean, which means that 231 overturned calls among 879 challenges is not a significantly high result.

5 0

2 years ago

Sophia invests $6,100 in a retirement account with a fixed annual interest rate of 5% compounded monthly. What will the account

kogti [31]

Answer:

come join me 83985970864 (Passcode: quarter4)

Step-by-step explanation:

8 0

2 years ago

What are the exact values of sin(2π3radians) and cos(2π3radians)

deff fn [24]

We know that
2π/3 radians-------> convert to degrees-----> 2*180/3---> 120°
120°=90°+30°

Part a) Find <span>sin(2π/3)
</span>sin(2π/3)=sin (90°+30°)
we know that
sin (A+B)=sin A*cos B+cos A*sin B
so
sin (90°+30°)=sin 90*cos 30+cos 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
sin (90°+30°)=1*√3/2+0*1/2-----> √3/2

the answer part a) is
sin(2π/3)=√3/2

Part b) Find cos (2π/3)
cos (2π/3)=cos (90°+30°)
we know that
cos (A+B)=cos A*cos B-sin A*sin B
so
cos (90°+30°)=cos 90*cos 30-sin 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
cos (90°+30°)=0*√3/2-1*1/2----> -1/2

the answer part b) is
cos (2π/3)=-1/2

8 0

2 years ago

A doctoral student wants to determine the relationship between steps per minute and the time it takes to walk 100 feet in

Rina8888 [55]

Using correlation coefficients, it is found that that the correct option is given as follows:

The correlation would stay the same because the change in units for time would have no effect on it.

<h3>What is a correlation coefficient?</h3>

It is an index that measures correlation between two variables, assuming values between -1 and 1.

If it is positive, the relation is positive, that is, they are direct proportional. If it is negative, they are inverse proportional.

If the absolute value of the correlation coefficient is greater than 0.6, the relationship is strong.

The correlation coefficient does not have units, hence if the units of the measures is changed, the coefficient remains constant, which means that the correct option is given by:

The correlation would stay the same because the change in units for time would have no effect on it.

More can be learned about correlation coefficients at brainly.com/question/25815006

#SPJ1

7 0

1 year ago