We know that a sample of 1800 computer chips revealed that 53% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature states that 54% of the chips do not fail in the first 1000 hours of their use.

We get that:

$n=1800\\\\p_1=53\%=0.53\\\\p_2=54\%=0.54\\$

We calculate the standar deviation:

$\sigma=\sqrt{\frac{0.53 \cdot (1-0.53)}{n}}=\sqrt{\frac{0.53 \cdot 0.47}{1800}}=0.01176$

We calculate the value of the test statistic:

$z=\frac{p_1-p_2}{\sigma}=\frac{0.53-0.54}{0.01176}=-0.85$

So the value of the test statistic is -0.85.

5 0

3 years ago

MATH: EXPONENTIAL WORK PROBLEM 1. HELP PLEASE! 13 pts

Strike441 [17]

The amount of the radioactive substance is 374.6 g

<h3>How to determine the amount of radioactive substance?</h3>

The given parameters are:

Initial, a = 424 mg
Rate, r = 6%
Time, t = 2 hours

The amount of the radioactive substance is calculated as:

A(t) = a(1 - r)^t

This gives

A(t) = 424 * (1 - 6%)^t

At 2 hours, we have:

A(2) = 424 * (1 - 6%)^2

Evaluate

A(2) = 374.6

Hence, the amount of the radioactive substance is 374.6 g

Read more about exponential functions at:

brainly.com/question/2456547

#SPJ1

4 0

2 years ago

What is the value of the expression f(-3) + 2f(-1) - f (4)<br><br> PLEASE HELP NO LINKS

Bas_tet [7]

Answer:

Step-by-step explanation:

Find f(-3) :

f(x) = x² + 2x for x ≤ -3

That means for those values of x, less than or equal to -3, this is the function.

So, f(-3) = (-3)² + 2(-3) = 9 - 6 = 3

Now, f(-1) :

From the given data, we see it is: f(x) = 2 $(\frac{1}{3} )^{2x}$

We take this because -1 lies between -3 and 4.

Now, f(-1) = 2 $(\frac{1}{3} )^{2(-1)}$

=> $f = (-1) = 2(3)^{2} = 2 (9) = 18$

For f(4) :

Clearly, the function is: $f (x) = \frac{2x - 5}{x-7}$

$f (4) = \frac{2(4)-5}{4-7} = \frac{3}{-3} = -1$

Therefore, <u>f(-3) + f(-1) - f(4) = 3 + 18 - (-1) = 3 + 18 + 1 = 22.</u>

5 0

2 years ago

What is the least number of congruency statements needed to be stated in a triangle congruency proof to prove triangles are cong

amm1812

Answer:

Step-by-step explanation:

The answer should be 3? Geometry.

6 0

2 years ago