Evaluate the function. Find f(5). f(x)=2x2-1. The second 2 is a exponent

on the football team, two out of every seven players are seniors. if the team has 84 players, how many are not seniors.

zaharov [31]

There are 60 players on football team that are not seniors.

Step-by-step explanation:

<u>Method 1:</u>

Given

Total students = 84

Also given that

2 out of 7 are seniors

Which is 2/7

So in order to find the total number of seniors we will multiply the whole number of students to 2/7

$Senior\ students = \frac{2}{7} * 84\\= 24$

So there are 24 seniors on the football team.

Players that are not seniors = 84 - 24 = 60

There are 60 players who are not seniors.

<u>Method 2:</u>

We can divide the total number by 7, to get how many sets of 7 players will be there

= 84/7 = 12

Now,

Multiplying 12 with 2 will give us the number of seniors in football team.

12*2 = 24 seniors

So,

Not seniors =84-24 = 60

Keywords: Percentage, Units

Learn more about percentage at:

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7 0

3 years ago

For the following hypothesis test, H0: μ ≥ 150Ha: μ < 150the test statistic a. must be positive. b. must be negative. c. can

Virty [35]

Answer:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

And since we are conducting a lower unilateral lest then we expected that the value for the statistic would be negative. And the correct answer would be:

b. must be negative

Step-by-step explanation:

Data given and notation

$\bar X$ represent the sample mean

$s$ represent the standard deviation for the sample

$n$ sample size

$\mu_o =150$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to determine if the mean is lower than 150, the system of hypothesis would be:

Null hypothesis: $\mu \geq 150$

Alternative hypothesis: $\mu < 150$

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

And since we are conducting a lower unilateral lest then we expected that the value for the statistic would be negative. And the correct answer would be:

b. must be negative

7 0

4 years ago

Which expression is equal to 4-6

frez [133]

-1-1 or 2-4 or 3-5 or 6-8 or 7-9 or 8-10

6 0

3 years ago

Suppose in the University of Manitoba, 40% of the students live in apartments. If 600 students are randomly selected, then the a

just olya [345]

Answer:

$P(200\leq X\leq 400)=P(\frac{200-240}{12}\leq \frac{X-\mu}{\sigma}\leq \frac{400-240}{12})=P(-3.33\leq Z \leq 13.33)$

$=P(Z$

So then the correct answer would be:

B) .9996

Step-by-step explanation:

The exact way to solve this problem is using the binomial distribution, assuming that our random variable of interest is "number of students living in apartments" represented by X and $X \sim Bin(n=600, p =0.4)$

And we want this probability:

$P(200 \leq X \leq 400) [tex]In order to find this probability we can use the foloowing excel code:"=BINOM.DIST(400,600,0.4,TRUE)-BINOM.DIST(199,600,0.4,TRUE)"And we got:[tex] P(200 \leq X \leq 400) =0.999675[tex]But for this case the problem says that we need to approximate, so then we can use the normal approximation to the normal distribution. We need to check the conditions in order to use the normal approximation.
[tex]np=600*0.4=240\geq 10$

$n(1-p)=600*(1-0.4)=360 \geq 10$

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:

$E(X)=np=600*0.4=240$

$\sigma=\sqrt{np(1-p)}=\sqrt{600*0.4(1-0.4)}=12$

And then $X \sim N (\mu = 240, \sigma= 12)$

And we are interested on the following probability:

$P(200\leq X\leq 400)=P(\frac{200-240}{12}\leq \frac{X-\mu}{\sigma}\leq \frac{400-240}{12})=P(-3.33\leq Z \leq 13.33)$

$=P(Z$

So then the correct answer would be:

B) .9996

6 0

3 years ago

F(x) = 3 sin x + 3 cos x

Darina [25.2K]

F ( x ) = 3 sim x + 3 cos x
f ` ( x ) = 3 cos x - 3 sin x
f `` ( x ) = - 3 sin x - 3 cos x = - 3 ( sin x + cos x )
The inflection points:
- 3 ( sin x + cos x ) = 0
sin x + cos x = 0
sin x = - cos x / : cos x
tan x = - 1
x 1 = 3π / 4
x 2 = 7π / 4
The function is concave up when f``(x) > 0
- 3( sin x+ cos x ) > 0
sin x + cos x < 0
tan x < - 1
f is concave up for:
x ∈ ( π/2, 3π/4 ) ∪ ( 3π/2, 7π/4)
f is concave down for:
x ∈ ( 0, π/2 ) ∪ ( 3π / 4, 3π/2 ) ∪ ( 7π / 4, 2 π ).

5 0

4 years ago

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