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3 years ago

Select the correct answer for when you evaluate the following function at f(5):

Mathematics

2 answers:

quester [9]3 years ago

5 0

A because (-5)^2 = 25 + 2(5) =35-1=34

klio [65]3 years ago

3 0

A. 34
f(5)=5^2+2x-1
you replace all x with 5
5^2=25
2(5)= 10
f(5)=25+10-1
f(5)=34

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Please answer! Thank you! :)

Aleonysh [2.5K]

Answer:

i think is n = 4. Sorry if wrong.

Step-by-step explanation:

5 0

3 years ago

With individual lines at its various windows, a post office finds that the standard deviation for normally distributed waiting t

anastassius [24]

Answer:

H0 : σ²= 7.2²

H1 : σ² < 7.2

We can conclude that the mean waiting time of customers vary less, Than 7.2 minutes.

Step-by-step explanation:

H0 : σ²= 7.2²

H1 : σ² < 7.2²

The test statistic :

X² = [(n - 1)*s² ÷ σ²]

s² = 3.5

n = sample size = 25. ; s²

X² = [(25 -1)*3.5² ÷ 7.2²

X² = (24 * 3.5^2) / 7.2^2

X² = 5.67

Pvalue from Chisquare statistic :

P(X² < 5.67) = 0.000042

Pvalue < α ; we reject the Null.

Hence, we can conclude that the mean waiting time of customers vary less, Than 7.2 minutes.

5 0

3 years ago

A survey was conducted two years ago asking college students their top motivations for using a credit card. To determine whether

salantis [7]

Answer:

See explanation

Step-by-step explanation:

Solution:-

- A survey was conducted among the College students for their motivations of using credit cards two years ago. A randomly selected group of sample size n = 425 college students were selected.

- The results of the survey test taken 2 years ago and recent study are as follows:

Old Survey ( % ) New survey ( Frequency )

Reward 27 112

Low rate 23 96

Cash back 21 109

Discount 9 48

Others 20 60

- We are to test the claim for any changes in the expected distribution.

We will state the hypothesis accordingly:

Null hypothesis: The expected distribution obtained 2 years ago for the motivation behind the use of credit cards are as follows: Rewards = 27% , Low rate = 23%, Cash back = 21%, Discount = 9%, Others = 20%

Alternate Hypothesis: Any changes observed in the expected distribution of proportion of reasons for the use of credit cards by college students.

( We are to test this claim - Ha )

We apply the chi-square test for independence.

- A chi-square test for independence compares two variables in a contingency table to see if they are related. In a more general sense, it tests to see whether distributions of categorical variables differ from each other.

- We will compute the chi-square test statistics ( X^2 ) according to the following formula:

$X^2 = Sum [ \frac{(O_i - E_i)^2}{Ei} ]$

Where,

O_i : The observed value for ith data point

E_i : The expected value for ith data point.

- We have 5 data points.

So, Oi :Rewards = 27% , Low rate = 23%, Cash back = 21%, Discount = 9%, Others = 20% from a group of n = 425.

Ei : Rewards = 112 , Low rate = 96, Cash back = 109, Discount = 48, Others = 60.

Therefore,

$X^2 = [ \frac{(112 - 425*0.27)^2}{425*0.27} + \frac{(96 - 425*0.23)^2}{425*0.23} + \frac{(109 - 425*0.21)^2}{425*0.21} + \frac{(48 - 425*0.09)^2}{425*0.09} + \frac{(60 - 425*0.20)^2}{425*0.20}]\\\\X^2 = [ 0.06590 + 0.03132 + 4.37044 + 2.48529 + 7.35294]\\\\X^2 = 14.30589$

- Then we determine the chi-square critical value ( X^2- critical ). The two parameters for evaluating the X^2- critical are:

Significance Level ( α ) = 0.10

Degree of freedom ( v ) = Data points - 1 = 5 - 1 = 4

Therefore,

X^2-critical = X^2_α,v = X^2_0.1,4

X^2-critical = 7.779

- We see that X^2 test value = 14.30589 is greater than the X^2-critical value = 7.779. The test statistics value lies in the rejection region. Hence, the Null hypothesis is rejected.

Conclusion:-

This provides us enough evidence to conclude that there as been a change in the claimed/expected distribution of the motivations of college students to use credit cards.

6 0

4 years ago

If x is the midpoint of ZW, then ZX=XW

sasho [114]

Answer:

True.

Step-by-step explanation:

By definition of a mid point, it is located in the middle of two connected points. This means that the split is equal on both sides.

IF X is the midpoint of ZW, then ZX = XW.

4 0

3 years ago

18. Use Pascal's triangle to find the coefficients of the expanded polynomial (a + b)^3.

Over [174]

Answer:

Step-by-step explanation:

Hello, let's compute the first lines of the Pascal's triangle.

1 1

1 2 1

1 3 3 1

So for this question,

$(a+b)^3=a^3+3a^2b+3ab^2+b^3$

And then, the correct answer is A.

Thank you

6 0

4 years ago