What is the answer to 9(

What is the square root of -225

NemiM [27]

Answer:

15i

Step-by-step explanation:

since 15 x 15 is 225, the imaginary number comes into play here. i x i = -1, so 15i x 15i = -225

8 0

3 years ago

Read 2 more answers

You want to be able to withdraw $25,000 from your account each year for 20 years after you retire.

Nina [5.8K]

Answer:

When using formulas in application, or memorizing them for tests, it is helpful to note the similarities and differences in the formulas so you don’t mix them up. Compare the formulas for savings annuities vs payout annuities.

Savings Annuity Payout Annuity

P

N

=

d

(

1

+

r

k

)

N

k

−

1

)

(

r

k

)

P

0

=

d

(

1

−

(

1

+

r

k

)

−

N

k

)

(

r

k

)

PAYOUT ANNUITY FORMULA

P

0

=

d

(

1

−

(

1

+

r

k

)

−

N

k

)

(

r

k

)

P0 is the balance in the account at the beginning (starting amount, or principal).

d is the regular withdrawal (the amount you take out each year, each month, etc.)

r is the annual interest rate (in decimal form. Example: 5% = 0.05)

k is the number of compounding periods in one year.

N is the number of years we plan to take withdrawals

3 0

2 years ago

Of a group of randomly selected adults, 360 identified themselves as manual laborers, 280 identified themselves as non-manual wa

Wittaler [7]

Answer:

We are 95% confident that the percent of executives who prefer trucks is between 19.43% and 33.06%

Step-by-step explanation:

We are given that in a group of randomly selected adults, 160 identified themselves as executives.

n = 160

Also we are given that 42 of executives preferred trucks.

So the proportion of executives who prefer trucks is given by

p = 42/160

p = 0.2625

We are asked to find the 95% confidence interval for the percent of executives who prefer trucks.

We can use normal distribution for this problem if the following conditions are satisfied.

n×p ≥ 10

160×0.2625 ≥ 10

42 ≥ 10 (satisfied)

n×(1 - p) ≥ 10

160×(1 - 0.2625) ≥ 10

118 ≥ 10 (satisfied)

The required confidence interval is given by

$p \pm z\times \sqrt{\frac{p(1-p)}{n} }$

Where p is the proportion of executives who prefer trucks, n is the number of executives and z is the z-score corresponding to the confidence level of 95%.

Form the z-table, the z-score corresponding to the confidence level of 95% is 1.96

$p \pm z\times \sqrt{\frac{p(1-p)}{n} }$

$0.2625 \pm 1.96\times \sqrt{\frac{0.2625(1-0.2625)}{160} }$

$0.2625 \pm 1.96\times 0.03478$

$0.2625 \pm 0.06816$

$0.2625 - 0.06816, \: 0.2625 + 0.06816$

$(0.1943, \: 0.3306)$

$(19.43\%, \: 33.06\%)$

Therefore, we are 95% confident that the percent of executives who prefer trucks is between 19.43% and 33.06%

5 0

3 years ago

HELP ME PLEASE!!

LUCKY_DIMON [66]

Using a system of equation, we have that:

a)

x, which is the cost of on-site service.
y, which is the cost of at-store service.
z, which is the cost of by-mail service.

b)

The system is:

$x = 3y$

$z = y - 10$

$15x + 40y + 5z = 3100$

c)

The cost of one on-site repair service is of $90.

Item a:

The variables are:

x, which is the cost of on-site service.
y, which is the cost of at-store service.
z, which is the cost of by-mail service.

Item b:

On-site service costs 3 times as much as at-store service, thus:

$x = 3y$

By mail service costs $10 less than at-store service, thus:

$z = y - 10$

Last week, the shop completed 15 services on-site, 40 services at-store, and 5 services by mail for total sales of $3100, thus:

$15x + 40y + 5z = 3100$

The system is:

$x = 3y$

$z = y - 10$

$15x + 40y + 5z = 3100$

Item c:

The cost of one on-site repair service is x.
First, replacing the first two equations into the third, we find y, and then with it we find x.

$15x + 40y + 5z = 3100$

$15(4y) + 40y + 5(y - 10) = 3100$

$60y + 40y + 5y = 3150$

$105y = 3150$

$y = \frac{3150}{105}$

$y = 30$

Then

$x = 3y = 3(30) = 90$

The cost of one on-site repair service is of $90.

A similar problem is given at brainly.com/question/24823220

3 0

2 years ago

The number of calories Kira burns while riding a bike varies directly with the number of hours the bike is ridden. How many calo

Veseljchak [2.6K]

480 since 1 hour=60 minutes. Look on the graph and you can see that the line looks like its 500 but since the answer choices dont say 500 it has to be 480 which is the closest

4 0

3 years ago

What is the answer to 9(–12)