What is the area of a triangle with a base of 15 1/4 inches and a height of 10 inches?

since the line is parallel it has the same slope so we have y = 3x + b. plug in the point (2,10) to get 10 = 3*2 + b, so b=4. so the equation is y = 3x +4

6 0

2 years ago

Engineers at a large automobile manufacturing company are trying to decide whether to purchase brand A or brand B tires for the

andre [41]

Answer:

$s_p =\sqrt{\frac{(12 -1)(5100)^2 +(12-1)(5900)^2}{12 +12 -2}}=5514.526$

$t=\frac{(37900-39800)-0}{5514.526\sqrt{\frac{1}{12}+\frac{1}{12}}}}=-0.844$

$p_v =2*P(t_{22}$

Comparing the p value with a significance level for example $\alpha=0.1$ 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 conclude that the true means are not significantly different.

Step-by-step explanation:

Data given and notation

$\bar X_{A}=37900$ represent the mean for A

$\bar X_{B}=39800$ represent the mean for B

$s_{A}=5110$ represent the sample standard deviation for A

$s_{B}=5900$ represent the sample standard deviation for B

$n_{A}=12$ sample size for the group A

$n_{B}=12$ sample size for the group B

$\alpha$ 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 means are equal or not, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{B}= 0$

Alternative hypothesis: $\mu_{A} - \mu_{B}\neq 0$

We don't have the population standard deviation's but we assume that the population deviation is equal for both populations, so we can apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{A}-\bar X_{B})-\Delta}{s_p\sqrt{\frac{1}{n_{A}}+\frac{1}{n_{B}}}}$ (1)

Where $s_p$ represent the standard deviation pooled given by:

$s_p =\sqrt{\frac{(n_A -1)s^2_A +(n_B -1)s^2_B}{n_A +n_B -2}}$

$s_p =\sqrt{\frac{(12 -1)(5100)^2 +(12-1)(5900)^2}{12 +12 -2}}=5514.526$

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:

$t=\frac{(37900-39800)-0}{5514.526\sqrt{\frac{1}{12}+\frac{1}{12}}}}=-0.844$

P value

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

$df=n_A +n_{B}-2=12+12-2=22$

Since is a two tailed test the p value would be:

$p_v =2*P(t_{22}$

Comparing the p value with a significance level for example $\alpha=0.1$ 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 conclude that the true means are not significantly different.

6 0

3 years ago