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4 years ago

A convenience store manager wants to find out

Mathematics

2 answers:

scoundrel [369]4 years ago

8 0

Answer: systematic random sampling

Step-by-step explanation:

Debora [2.8K]4 years ago

5 0

Answer:

Systematic random sampling

Step-by-step explanation:

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Find the average rate of change for f(x) = x2 − 3x − 10 from x = 4 to x = 6. A) 5 Reactivate B) 7 C) 9 Reactivate D) 11

White raven [17]

Answer:Rate of change is 7

Option B is correct.

Step-by-step explanation:

We need to find the average rate of change for $f(x)=x^2-3x-10$ from x = 4 to x = 6

The formula used to find average rate of change is:

$Rate\,\,of\,\,change=\frac{f(b)-f(a)}{b-a}$

Where b = 6 and x = 4

Finding f(6):

$f(x)=x^2-3x-10\\f(6)=(6)^2-3(6)-10\\f(6)=36-18-10\\f(6)=36-28\\f(6)=8$

Finding f(4):

$f(x)=x^2-3x-10\\f(4)=(4)^2-3(4)-10\\f(4)=16-12-10\\f(4)=16-22\\f(4)=-6$

Now Putting values:

$Rate\,\,of\,\,change=\frac{f(b)-f(a)}{b-a}$

$Rate\,\,of\,\,change=\frac{8-(-6)}{6-4}\\Rate\,\,of\,\,change=\frac{8+6}{2}\\Rate\,\,of\,\,change=\frac{14}{2}\\Rate\,\,of\,\,change=7$

So, Rate of change is 7

Option B is correct.

Keywords: Rate of Change

Learn more about Rate of Change at:

#learnwithBrainly

8 0

3 years ago

For the following problem, assume that all given angles are in simplest form, so that if A is in QIV you may assume that 270° &l

d1i1m1o1n [39]

Answer:

Step-by-step explanation:

Given that angle A is in IV quadrant

So A/2 would be in II quadrant.

sin A = -1/3

cos A = $\sqrt{1-sin^2 A} =\frac{2\sqrt{2} }{3}$

(cos A is positive since in IV quadrant)

Using this we can find cos A/2

$cosA = 2cos^2 \frac{A}{2} -1\\Or cos \frac{A}{2} =-\sqrt{\frac{1+cosA}{2} } =-\sqrt{\frac{3+2\sqrt{2} }{6} }$

3 0

3 years ago

A survey reported in Time magazine included the question ‘‘Do you favor a federal law requiring a day waiting period to purchase

il63 [147K]

Answer:

The 90% confidence interval for the difference between proportions is (-0.260, -0.165).

Step-by-step explanation:

The question is incomplete. The complete question is:

"A survey reported in Time magazine included the question ‘‘Do you favor a federal law requiring a 15 day waiting period to purchase a gun?” Results from a random sample of US citizens showed that 318 of the 520 men who were surveyed supported this proposed law while 379 of the 460 women sampled said ‘‘yes”. Use this information to find a 90% confidence interval for the difference in the two proportions, pm - pw. Subscript pm is the proportion of men who support the proposed law and pw is the proportion of women who support the proposed law. (Round answers to 3 decimal places.)"

We want to calculate the bounds of a 90% confidence interval.

For a 90% CI, the critical value for z is z=1.645.

The sample of men, of size nm=-0.26 has a proportion of pm=0.612.

$p_m=X_m/n_m=318/520=0.612$

The sample 2, of size nw= has a proportion of pw=0.824.

$p_w=X_w/n_w=379/460=0.824$

The difference between proportions is (pm-pw)=-0.212.

$p_d=p_m-p_w=0.612-0.824=-0.212$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_m+X_w}{n_m+n_w}=\dfrac{318+379}{520+460}=\dfrac{697}{980}=0.711$

The estimated standard error of the difference between means is computed using the formula:

$s_{pm-pw}=\sqrt{\dfrac{p(1-p)}{n_m}+\dfrac{p(1-p)}{n_w}}=\sqrt{\dfrac{0.711*0.289}{520}+\dfrac{0.711*0.289}{460}}\\\\\\s_{pm-pw}=\sqrt{0.00039+0.00045}=\sqrt{0.001}=0.029$