1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jarptica [38.1K]
3 years ago
7

Susan invests

Mathematics
1 answer:
Arturiano [62]3 years ago
5 0
Let f=amount invested at 4% and e=amount invested at 8%

0.04f+.08e=800

However, e=2f so the above equation becomes:

0.04f+0.08(2f)=800

0.04f+0.16f=800

0.2f=800

f=$4000, since e=2f

e=$8000

So Susan invested $4000 at 4% and $8000 at 8%.
You might be interested in
Are the expressions 2x+8 and 2(x+4)+4 equivalent
andriy [413]

Answer:

No

Step-by-step explanation:

2x+8 2(x+4)+4

2(x)+2(4)+4

2x+8+4

2x+12

4 0
3 years ago
Read 2 more answers
(a) An article in a medical journal suggested that approximately 14% of such operations result in complications. Using this esti
aev [14]

This question is incomplete, the complete question is;

Surgical complications: A medical researcher wants to construct a

99.5% confidence interval for the proportion of knee replacement surgeries that result in complications.

- An article in a medical journal suggested that approximately 14% of such operations result in complications. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.08?

Answer: a sample of operations needed is 149

Step-by-step explanation:

Given that;

confidence interval = 99.5% = 0.995 so

margin of error E = 0.08

p = 14% = 0.14

now we obtain the critical value of z t the 99.5 confidence interval

∝ = 1 - confidence interval

∝ = 1 - 0.995

∝ = 0.005

∝/2 = 0.0025

obtaining the area of probability in the right tail

Area of probability to the right is = 1 - 0.0025 = 0.9975

from probability table; critical value of t =2.81

using the formula

n = p( 1 - p ) [ (z_∝/2)/E)² ]

so we substitute  

n = 0.14 ( 1 - 0.14 ) [ 2.81 / 0.08 )²  

n = (0.14 × 0.86 ) × 1233.7656

n = 148.5453 ≈ 149

Therefore , a sample of operations needed is 149

4 0
3 years ago
X^2 - 9x -10 =0 has a discriminant of: a. 121 b. 72 c. -359 d. 41 e. 136
Feliz [49]
In the standard form of quadratic
ax^{2} +bx+c
the discriminant is
b^{2} -4ac
In your quadratic, a = 1, b = -9 and c = -10
Now you need to plug these values into the expression for the discriminant.
7 0
3 years ago
Jose can read 7 pages of his book in 5 minutes at this rate how long will it take for him to read the full 175 page book
Agata [3.3K]

Answer:

125 minutes

Step-by-step explanation:


7 0
3 years ago
What is 1 4/10 + 2 2/10
telo118 [61]
1+2=3. 4/10+2/10=6/10. 3+ 6/10=3 6/10
6 0
3 years ago
Other questions:
  • How do you graph equations
    5·1 answer
  • The total area of two square windows is 1025 in2. Each side of the larger window is 5 in longer than the sides of the smaller wi
    10·2 answers
  • Donald bought 10 woodcarvings for a total of $220. If they were all the same price, how much did he pay for each wood carving?
    12·2 answers
  • Help please thanks :)
    5·2 answers
  • Solve for e 7(2e-1)-3=6+6e du
    13·1 answer
  • Any help I would really appreciate it
    7·1 answer
  • What is the result of 8 divided by 3/8
    8·2 answers
  • Joe's Hot Dog Stand is only open for lunch. Of today's sales, 26% came from selling plain hot dogs. Since the hot dog stand made
    15·1 answer
  • Karen picked apples at the Carter Apple Orchard this weekend. She made a graph to show how many apples she picked.
    13·2 answers
  • 1.6 + 3 x 4 - 2 divided by 2<br> An PEMDAS question, pretty easy!
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!