Bob bought the 24 fish for $51.36. How much did each fish cost him? Show your calculation

14. In a month-long randomized comparative experiment, participants were

kobusy [5.1K]

Answer: A

Step-by-step explanation:

Confidence interval for the difference in the two proportions is written as

Difference in sample proportions ± margin of error

Sample proportion, p = x/n

Where x = number of success

n = number of samples

For the first treatment,

x = 35

n1 = 50

p1 = 35/50 = 0.7

For the second treatment,

x = 16

n2 = 40

p2 = 16/40 = 0.4

Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.99 = 0.01

α/2 = 0.01/2 = 0.005

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.005 = 0.995

The z score corresponding to the area on the z table is 2.576. Thus, the z score for 99% confidence level is 2.576

Margin of error = 2.576 × √[0.7(1 - 0.7)/50 + 0.4(1 - 0.4)/40]

= 2.576 × 0.10099504938

= 0.26

Confidence interval = 0.7 - 0.4 ± 0.26

= 0.3 ± 0.26

Option A is correct

4 0

4 years ago

Mai's younger brother tells her that 10/7 equal to 2‾√ 2 2‾√ 2 . Mai knows this can't be right, because 10/7 is rational and 2‾√

makvit [3.9K]

Answer:

The number 10/7 is a rational number, which means it can be expressed as a fraction. Also, if we divide it would give a decimal infinite periodical number, which means it has a pattern on its decimal numbers.

On the other hand, the square root of 2 is irrational number, that means it can't be expressed as a fraction, because its decimal numbers don't have any pattern at all.

So, Mai's brother can see these type of numbers as crazy (irrational numbers) and sane (rational numbers).

At last, another important characteristic to shows that they aren't equal is that they don't have the exactly decimal numbers.

6 0

3 years ago

CAN U GUYS PLZ HELP!!

attashe74 [19]

Answer:

C. 5/2

Step-by-step explanation:

Two points that the graph passes through are (-5, -4) and (-3, 1). This tells us that the graph goes up 5 units at the same rate that it goes right 2 units. Since the slope of a graph is simply the movement of the y values over the movement of the x values, the slope of this graph is 5/2, which is option C.

6 0

3 years ago

-

qwelly [4]

Answer:

8.3

Step-by-step explanation:

4 0

3 years ago

These are the cost and revenue functions for a line of trumpets sold at a music store:

Maslowich

Answer:

168 trumpets for $1702

Step-by-step explanation:

Profit is the measure to be maximized. We are given revenue and cost relationships as a function of units, x (trumpets). Profit is the difference:

Profit = Revenue[R(x)] - Cost[C(x)]

Profit = (76x – 0.25x^2) - (-7.75x + 5,312.5)

Profit = 76x - 0.25x^2 + 7.75x - 5,312.5

Profit = - 0.25x^2 + 83.75x - 5312.5

At this point we can find the trumpets needed for maximum profit by either of two approaches: algebraic and graphing. I'll do both.

Mathematically

The first derivative will give us the slope of this function for any value of x. The maximum will have a slope of zero (the curve changes direction at that point). Take the first derivative and set that equal to 0 and solve for x.

First derivative:

d(Profit)/dx = - 2(0.25x) + 83.75

d(Profit)/dx = - 0.50x + 83.75

0 = - 0.50x + 83.75

0.50x = 83.75

x = 167.5 trumpets

Graphically

Plot the profit function and look for the maximum. The graph is attached. The maximum is 167.5 trumpets.

Round up or down to get a whole trumpet. I'll go up: 168 trumpets.

Maximum Profit

Solve the profit equation for 168 trumpets:

Profit = - 0.25x^2 + 83.75x - 5312.5

Profit = - 0.25(168)^2 + 83.75(168) - 5312.5

Profit = $1702

4 0

3 years ago