Part a), solve this system of equations:
x + y = 5
x - y = 2.25
2x = 7.25
x = 3.625
y = 1.375

part b), solve this system of equations:
x + y = 5
x = 3y
y = 1.25
x = 3.75

3 0

2 years ago

Read 2 more answers

Here is a simple probability model for multiple-choice tests. Suppose that each student has probability p of correctly answering

Alla [95]

Answer:

a) The probability that Jodi scores 78% or lower on a 100-question test is 4%.

b) The probability that Jodi scores 78% or lower on a 250-question test is 0.023%.

Step-by-step explanation:

a) To approximate this distribution we have to calculate the mean and the standard distribution.

The mean is the proportion p=0.85.

The standard deviation can be calculates as:

$\sigma=\sqrt{\frac{p(1-p)}{n} }= \sqrt{\frac{0.85*(1-0.85)}{100} }=0.04$

To calculate the probability that Jodi scores 78% or less on a 100-question test, we first calculate the z-value:

$z=\frac{p-p_0}{\sigma} =\frac{0.78-0.85}{0.04} =-1.75$

The probability for this value of z is

$P(x$

The probability that Jodi scores 78% or lower on a 100-question test is 4%.

b) In this case, the number of questions is 250, so the standard deviation needs to be calculated again:

$\sigma=\sqrt{\frac{p(1-p)}{n} }= \sqrt{\frac{0.85*(1-0.85)}{250} }=0.02$

To calculate the probability that Jodi scores 78% or less on a 250-question test, we first calculate the z-value:

$z=\frac{p-p_0}{\sigma} =\frac{0.78-0.85}{0.02} =-3.5$

The probability for this value of z is

$P(x$

The probability that Jodi scores 78% or lower on a 250-question test is 0.023%.

6 0

2 years ago

Whats the overall homework score ?

Pavel [41]

Answer:

the answer is h 86.8 first you gotta take all the numbers then drop the two lowest then you multiply the ones you hsve left then divide it by the number of grsdes there is

8 0

3 years ago

A kitchen sink faucet streams 0.5 gallon of water in 10 seconds. A bathroom sink faucet stream 0.75 gallon of water in 18 second

Masteriza [31]

Answer:

kitchen sink faucet stream

Step-by-step explanation:

with kitchen sink faucet you fill 0.05gallons of water per second you get that by dividing 0.5 by 10

and the bathroom sink faucet does 0.041gallons of water per second you get that by dividing 0.75 by 18

7 0

2 years ago