12 − 7 = 2(3 + 5) + 6 − 17

Find f (2b^2) for (x)=x^2-4x

BlackZzzverrR [31]

Answer:

A

Step-by-step explanation:

We are given the function:

$f(x) = x^2 - 4x$

And we want to find:

$\displaystyle f(2b^2)$

Substitute:

$\displaystyle f(2b^2) =(2b^2)^2 -4(2b^2)$

And evaluate:

$\displaystyle \begin{aligned} f(2b^2) &=(2b^2)^2 -4(2b^2) \\ &=(4b^4) +(-8b^2) \\ &= 4b^4 - 8b^2 \end{aligned}$

In conclusion, our answer is A.

7 0

2 years ago

Which sampling method is generally considered the weakest?

babunello [35]

Answer – C. (Convenience sampling)

The sampling method that is generally considered the weakest is convenience sampling. This is because in convenience sampling, there is usually no inclusion criteria identified prior to the selection of subjects. Convenience sampling involves getting participants wherever you can conveniently find them. Typically, the first available participants (or any other primary data source, as the case may be) will be used for the research without any additional requirements.Other names by which convenience sampling is known are: Incidental Sampling, Chunk Sampling, and Accidental Sampling.

8 0

2 years ago

Read 2 more answers

Dylan Rieder is a statistics student investigating whether athletes have better balance than non-athletes for a thesis project.

Kobotan [32]

Answer:

$t=\frac{(3.7-4.1)-0}{\sqrt{\frac{1.1^2}{32}+\frac{1.3^2}{45}}}}=-1.457$

$p_v =P(t_{75}$

Comparing the p value with a significance level for example $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't say that the population mean for the athletes is significantly lower than the population mean for non athletes.

Step-by-step explanation:

Data given and notation

$\bar X_{A}=3.7$ represent the mean for athletes

$\bar X_{NA}=4.1$ represent the mean for non athletes

$s_{A}=1.1$ represent the sample standard deviation for athletes

$s_{NA}=1.3$ represent the sample standard deviation for non athletes

$n_{A}=32$ sample size for the group 2

$n_{NA}=45$ sample size for the group 2

$\alpha=0.01$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the population mean for athletes is lower than the population mean for non athletes, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{NA}\geq 0$

Alternative hypothesis: $\mu_{A} - \mu_{NA}< 0$

We don't have the population standard deviation's, we can apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{A}-\bar X_{NA})-\Delta}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{NA}}{n_{NA}}}}$ (1)

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(3.7-4.1)-0}{\sqrt{\frac{1.1^2}{32}+\frac{1.3^2}{45}}}}=-1.457$

P value

We need to find first the degrees of freedom given by:

$df=n_A +n_{NA}-2=32+45-2=75$

Since is a one left tailed test the p value would be:

$p_v =P(t_{75}$

Comparing the p value with a significance level for example $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't say that the population mean for the athletes is significantly lower than the population mean for non athletes.

5 0

2 years ago

Which expression is equivalent to (64y100) 1/2 8y10 8y50 32y10 32y50

TiliK225 [7]

Step-by-step explanation:

(64y100)1/2

1/2×64y 1/2×100

32y50

6 0

2 years ago

Use a quadratic equation to find two real numbers with a sum of 43 and a product of 306

Gwar [14]

(x + 9) (x + 34)
9 * 34 = 306
9 + 34 = 43

8 0

2 years ago