# The quality control manager at a light bulb manufacturing company needs to estimate the mean life of the light bulbs produced at the factory. The life of the bulbs is known to be normally distributed with a standard deviation (sigma) of 80 hours. A random sample of 16 light bulbs indicated a sample mean life of 1000 hours. What is a 95% confidence interval estimate (CIE) of the true mean life (m) of light bulbs produced in this factory

Step-by-step explanation:

Let X denotes a random variable that represents the life of the light bulbs produced at the factory.

As per given,

Critical z-value for 95% confidence interval : z* = 1.96

Confidence interval for population mean:

So, a 95% confidence interval estimate (CIE) of the true mean life (m) of light bulbs produced in this factory = (960.80,1039.20)

## Related Questions

Would give you brainliest whoever answers this correct first !!

6 is the answer to the question

HELP QUICK!!!L 18 16 12 10 4 32 34 36 38 40 14 46 54 50 08 The graph shows that as Fincreases, C o decreases increases is constant increases then decreases​

increases

Step-by-step explanation:

Since the lines goes up as the variable F increases( F is the horizontal variable), C will increase

The line increases because u can obviously see the line going up...

Step-by-step explanation:

(1 point) For the equation given below, evaluate ′ at the point (−1,2). (5−)^4+4^3=2433. ′ at (−1,2) =

Step-by-step explanation:

Given the equation

Find the derivative:

Substitute

then

Simplify The square root of 5 (6-4 the square root of 3)

7.75

Step-by-step explanation:

6-4=2

2 times the square root of 3=3.46410161514

square root of 5 times 3.46410161514=7.74596669242

to 2dp=7.75

When a water-cooled nuclear power plant is in operation, oxygen in the water is transmuted to nitrogen-17. After the reactor is shut down, the radiation from the nitrogen-17 decreases in such a way that the rate of change in the radiation level is directly proportional to the radiation level.Required:
Write a differential equation that expresses the rate of change in the radiation level in terms of the radiation level.

The differential equation is

Step-by-step explanation:

Differential equation for the rate of change in radiation level:

Rate of change indicates that the radiation level R varies in function of time t, which mathematically means that we have:

After the reactor is shut down, the radiation from the nitrogen-17 decreases in such a way that the rate of change in the radiation level is directly proportional to the radiation level.

Rate of change is k. Decreases means that k is negative. Proportional to the radiation level of R means that -k multiplies R. So the differential equation is:

Let n = 5.What is the value of the expression 9n2−2−n?