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3 years ago

Derive the equation of the parabola with a focus at (−5, 5) and a directrix of y = −1. (2 points)

Mathematics

1 answer:

love history [14]3 years ago

3 0

The focus is above the directrix, so the parabola opens upward—its vertical scale factor is positive (+1/12). The line of symmetry is x=-5, so the vertex form of the equation will have the factor (x -(-5))² = (x+5)². The choice that meets both these requirements is
D. f(x) = (1/12)(x + 5)² + 2

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What is the square rout of 56

Mars2501 [29]

$\sqrt{56}=\sqrt{4\cdot14}=\sqrt4\cdot\sqrt{14}=2\sqrt{14}$

6 0

3 years ago

I need help again. once again due TM helppp

vekshin1

Since the object is a cube, times 42 three times by itself. You have to do this because it is length x width x height. 42 x 42 x 42. The answer you're looking for is 74,088 cubic inches because it is three-dimensional.

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3 years ago

Read 2 more answers

5) In a certain supermarket, a sample of 60 customers who used a self-service checkout lane averaged 5.2 minutes of checkout tim

Ne4ueva [31]

Answer:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

$S_p=2.940$

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

$df=60+72-2=130$

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

Step-by-step explanation:

Data given

Our notation on this case :

$n_1 =60$ represent the sample size for people who used a self service

$n_2 =72$ represent the sample size for people who used a cashier

$\bar X_1 =5.2$ represent the sample mean for people who used a self service

$\bar X_2 =6.1$ represent the sample mean people who used a cashier

$s_1=3.1$ represent the sample standard deviation for people who used a self service

$s_2=2.8$ represent the sample standard deviation for people who used a cashier

Assumptions

When we have two independent samples from two normal distributions with equal variances we are assuming that

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

The statistic is given by:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}$

And t follows a t distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

$\S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

System of hypothesis

Null hypothesis: $\mu_1 \geq \mu_2$

Alternative hypothesis: $\mu_1 < \mu_2$

This system is equivalent to:

Null hypothesis: $\mu_1 - \mu_2 \geq 0$

Alternative hypothesis: $\mu_1 -\mu_2 < 0$

We can find the pooled variance:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

And the deviation would be just the square root of the variance:

$S_p=2.940$

The statistic is given by:

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

The degrees of freedom are given by:

$df=60+72-2=130$

And now we can calculate the p value with:

$p_v =P(t_{130}$

5 0

3 years ago

Please help *THIS IS ON PERSONAL FINANCIAL LITERACY "

Crank

Answer:

I think the answer is $56,600

Step-by-step explanation:

I'm pretty sure you're just going to add $63,000+$8,400+$2,900+$1,1000. Then when you get a total of $75,400 and then I think you are going to subtract $15,400 from $75,400, you should get $60,000 then subtract $3,400 and you get $56,600.

7 0

3 years ago

Please help me someone

AveGali [126]

Put the numbers of books you have read

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3 years ago