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3 years ago

Please help simple pre algebra!!!

Mathematics

2 answers:

malfutka [58]3 years ago

8 0

Answer:

Step-by-step explanation:

10.99

xxMikexx [17]3 years ago

3 0

C=pi(d)

So d=7ft

Then pi(7ft)=21.98

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Jan buys 3 bags of beads. Each bag contains 7 beads. Draw a bar diagram and write an addition equation and a multiplication equa

-Dominant- [34]

Answer:

- The diagram bar is attached.

- Addition equation: $7+7+7=21$

- Multiplication equation: $(3)(7)=21$

- How are the equation related? Each equation shows 3 groups of 7.

Step-by-step explanation:

We know that Jan buys 3 bags of beads and each bag contains 7 beads, then, you can draw the bar diagram shown attached.

Observe that the diagram has 3 blocks (each block represents a bag of bead) and there is a number 7 inside of each block (which is the number of beads contained in a bag).

Therefore:

- Add the numbers inside the blocks in order to get the addition equation that shows the number of beads Jan buys. This is:

$7+7+7=21$

- Multiply 3 blocks by 7 in order to get multiplication equation that show the number of beads Jan buys:

$(3)(7)=21$

The equations are related. Each one shows 3 groups of 7.

6 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:

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