# A manufacturer of college textbooks is interested in estimating the strength of the bindings produced by a particular binding machine. Strength can be measured by recording the force required to pull the pages from the binding. If this force is measured in pounds, how many books should be tested to estimate the average force required to break the binding to within 0.08 lb with 99% confidence? Assume that σ is known to be 0.72. (Exact answer required.)

538 books should be tested.

Step-by-step explanation:

We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, find the margin of error M as such

In which is the standard deviation of the population and n is the size of the sample.

How many books should be tested to estimate the average force required to break the binding to within 0.08 lb with 99% confidence?

n books should be tested.

n is found when

We have that

Rounding up

538 books should be tested.

## Related Questions

What is the measure of the angle?

155°

Step-by-step explanation:

The angle between the x and y axes is 90°. Adding 65° to that angle gives an angle measure of ...

... 90° +65° = 155°

In the year 2000 Florida's population was 16 million. since 2000, the state's population has grown about 2% each year. this means that Florida's population is growing exponentially. Find Florida's population in 2006​

Yes yes I will love to see if you get it right it is 12050

A drawer contains 3 tan sweaters and two black sweaters. You randomly choose two sweaters. What is the probability that both sweaters are black?

A = event that you select a black sweater
P(A) = 2/5 since there are 2 black out of 2+3 = 5 total

After you make a selection, we have the event
B = event that you select another black sweater assuming event A has happened already

P(B) = 1/4 because there's 1 black sweater left out of 5-1 = 4 left over

Multiply the probabilities
P(A and B) = P(A)*P(B)
P(A and B) = (2/5)*(1/4)
P(A and B) = 2/20
P(A and B) = 1/10

The answer as a fraction is 1/10
In decimal form, it is 0.1
As a percent, the answer is 10%

Jenny cut a wire into 4 equal pieces. The wire was originally 7.92 meters long. How long is each piece?

1.98 meters

Step-by-step explanation:

divide 7.92 by 4

(7.92)/4

1.98

Which expression is equal to “7 times the sum of a number and 4"?

Step-by-step explanation: Since the expression asks for 7 times the sum of a number and 4, you would put x + 4 in parentheses since multiplying 7 comes afterwards.

(15 POINTS) (FOLLOW DIRECTIONS ON ATTACHMENT!)

1. 5 / 6

2. 1 / 3

3. 3 / 6 or  1 / 2

Step-by-step explanation:

The probability that A is not yellow is 5 / 6

The probability that B is blue is 1 / 3

The probability that A is red is 3 / 6 or 1 / 2