1. f(x) = 9x^2 - 3 <br> Find the vertex

I need help, I am not familiar with this.

tekilochka [14]

Answer:

the first did it correct

Step-by-step explanation:

8 0

2 years ago

53% of U.S. adults have very little confidence in newspapers. You randomly select 10 U.S. adults. Find the probability that the

faltersainse [42]

Answer:

a

$P(X = 5) = 0.2423$

b

$P( X \ge 6 )= 0.4516$

c

$P( X < 4 )= 0.12694$

Step-by-step explanation:

From the question we are told that

The population proportion is p = 0.53

The sample size is n = 10

Generally the distribution of the confidence of US adults in newspapers follows a binomial distribution

i.e

$X \~ \ \ \ B(n , p)$

and the probability distribution function for binomial distribution is

$P(X = x) = ^{n}C_x * p^x * (1- p)^{n-x}$

Here C stands for combination hence we are going to be making use of the combination function in our calculators

Generally the probability that the number of U.S. adults who have very little confidence in newspapers is exactly five is mathematically represented as

$P(X = 5) = ^{10}C_5 * 0.53^5 * (1- 0.53)^{10-5}$

=> $P(X = 5) = 252 * 0.04182 * 0.023$

=> $P(X = 5) = 0.2423$

Generally the probability that the number of U.S. adults who have very little confidence in newspapers is at least six is mathematically represented as

$P( X \ge 6 )= P( X = 6) + P( X = 7) + P( X = 8) + P( X = 9) + P( X = 10)$

=> $P( X \ge 6 )= [^{10}C_6 * [0.53]^6 * (1- 0.53)^{10-6}] + [^{10}C_7 * [0.53]^7 * (1- 0.53)^{10-7}] + [^{10}C_8 * [0.53]^8 * (1- 0.53)^{10-8}] + [^{10}C_9 * [0.53]^9 * (1- 0.53)^{10-9}] + [^{10}C_{10} * [0.53]^{10} * (1- 0.53)^{10-10}]$

=> $P( X \ge 6 )= [0.227] + [0.1464] + [0.0619] + [0.0155] + [0.00082]$

=> $P( X \ge 6 )= 0.4516$

Generally the probability that the number of U.S. adults who have very little confidence in newspapers is less than four is mathematically represented as

$P( X < 4 )= P( X = 3) + P( X = 2) + P( X = 1) + P( X = 0)$

=> $P( X < 4 )= [^{10}C_3 * 0.53^3 * (1- 0.53)^{10-3}] + [^{10}C_2 * 0.53^2 * (1- 0.53)^{10-2}] + [^{10}C_1 * 0.53^1 * (1- 0.53)^{10-1}] + [^{10}C_0 * 0.53^0 * (1- 0.53)^{10-0}]$

=> $P( X < 4 )= 0.09051 + 0.03 + 0.0059 + 0.000526$

=> $P( X < 4 )= 0.12694$

5 0

2 years ago

The number of letters in Stephanie's full name is sixteen less than twice the number of letters in Amy's full name. If the numbe

Anestetic [448]

Answer:

19 letters

Step-by-step explanation:

Suppose Number of Amy's full name letters = X

Number of Stephanie's full name letters = Y

Now, according to given condition that ''number of letters in Stephanie's full name is sixteen less than twice the number of letters in Amy's full name'',

Equation 1 becomes

Y = 2X-16

Now, according to second condition, product of their names' letter is 418. So,

Equation 2 becomes

XY = 418

Deducing value of X from equation 1,

X = (Y+16)/2

Putting this value in equation 2 we get,

{(Y+16)/2}*Y = 418,

By simplifying this equation we get a quadritic equation

(Y^2)+16Y-836=0

By breaking middle term (You can use quadratic formula here as well)

(Y^2)+38Y-22Y-836=0

Y(Y+38)-22(Y+38)=0

(Y-22)(Y+38)=0

At this stage we have two values for Y,

Y=22, or Y=-38

Now considering only positive value since the number of letters in a name can not be in negative number,

Y=22,

So X=(Y+16)/2

X=19

7 0

3 years ago

Runner a averages 5 mph and run it B rat averages 6 mph these rates how much longer does it take runner A then runner be to run

Kipish [7]

Takes runner A 18 more minutes

8 0

3 years ago

When R2 is more useful than R in linear regression?

valina [46]

<span>Answer: Multiple R is the correlation between y and y^ in a regression model. It is always non-negative, but has no nice interpretation as a proportion of variance, unlike its square. I can't think of too many uses for it and only know of one stat package that routinely reports it, SPSS. Bivariate correlation only tells you about two variables at a time (though you can use partial correlation to remove other variables).</span>

6 0

2 years ago

1. f(x) = 9x^2 - 3 Find the vertex