The lengths of time (in hours) an incandescent light bulb can stay lit solidly are normally...

The lengths of time (in hours) an incandescent light bulb can stay lit solidly are normally distributed, with a mean of 62 hours and a standard deviation of 4.4 hours. Use this information to answer questions #16-20.

The top 2% of light bulbs can stay lit for at least how long?

What percent of light bulbs can last within one standard deviation of the mean, between 57.6 hours and 66.4 hours?

A company considers a bulb defective if it can only last 50 hours straight. What portion of light bulbs would this company consider defective?

An energy-efficient bulb can stay lit for at least 68 hours. What percent of incandescent bulbs can stay lit for that long?

What portion of light bulbs can stay lit for between 55 and 65 hours straight?

Expert Solution

orchestra answered 2 years ago

Suppose a gas-filled incandescent light bulb is manufactured so that the gas inside the bulb is...

Suppose a gas-filled incandescent light bulb is manufactured so that the gas inside the bulb is at atmospheric pressure when the bulb has a temperature of 20.0°C. Part (a) Find the gauge pressure, in standard atmospheres, inside such a bulb when it is hot, assuming its average temperature is 59.5ºC and neglecting any change in volume due to thermal expansion. Part (b) The actual final pressure for the light bulb will be less than calculated in part (a) because the...

The lifetime of light bulb is normally distributed with mean of 1400 hours and standard deviation of 200 hours.

The lifetime of light bulb is normally distributed with mean of 1400 hours and standard deviation of 200 hours. a. What is the probability that a randomly chosen light bulb will last for more than 1800 hours? b. What percentage of bulbs last between 1350 and 1550 hours? c. What percentage of bulbs last less than 1.5 standard deviations below the mean lifetime or longer than 1.5 standard deviations above the mean? d. Find a value k such that 20% of the bulbs last...

A 75 watt incandescent light bulb and an 18 watt compact fluorescent bulb are equally bright....

A 75 watt incandescent light bulb and an 18 watt compact fluorescent bulb are equally bright. How much warmer will an insulated closed 12 by 11 by 8.0 foot room get in 1.0 hour if it is lighted by an incandescent bulb than if it is lighted by a fluorescent bulb? At room temperature, the specific heat of air is 1.007 J/gC and its density is 1.2 g/L. The watt is the SI unit of power; 1 watt = 1...

The life in hours of a 75-watt light bulb is known to be approximately normally distributed,...

The life in hours of a 75-watt light bulb is known to be approximately normally distributed, with standard deviation σ = 25 hours. A random sample of 62 bulbs has a mean life of x-bar = 1,014 hours. Construct a 98% confidence interval around the true population mean life of the light bulb.

2. The lifetime of light bulb is normally distributed with mean of 1400 hours and standard...

2. The lifetime of light bulb is normally distributed with mean of 1400 hours and standard deviation of 200 hours. a. What is the probability that a randomly chosen light bulb will last for more than 1800 hours? b. What percentage of bulbs last between 1350 and 1550 hours? c. What percentage of bulbs last less than 1.5 standard deviations below the mean lifetime or longer than 1.5 standard deviations above the mean? d. Find a value k such that...

Suppose the life span of a light bulb is normally distributed with mean 1000 hours and...

Suppose the life span of a light bulb is normally distributed with mean 1000 hours and standard deviation 75 hours. (a) Find the 57th percentile of this distribution. (b) Find the probability that a random light bulb will last longer than 1100 hours. (c) Find the probability that the life span of a light bulb will be more than 3.14 standard deviations away from the mean. (d) Suppose you take a sample of 15 light bulbs and measure the average...

if the pilot light on a gas water heater will not stay lit... what seem to...

if the pilot light on a gas water heater will not stay lit... what seem to be the problem?

An incandescent light bulb uses a coiled filament of tungsten that is 580 mm long with...

An incandescent light bulb uses a coiled filament of tungsten that is 580 mm long with a diameter of 46.0 μm. At 20.0∘C tungsten has a resistivity of 5.25×10−8Ω⋅m. Its temperature coefficient of resistivity is 0.0045 (C∘)−1, and this remains accurate even at high temperatures. The temperature of the filament increases linearly with current, from 20∘C when no current flows to 2520∘C at 1.00 A of current. What is the resistance of the light bulb at 20∘C? What is the...

Calculate the rate of energy emitted from an incandescent tungsten halogen light bulb as a function...

Calculate the rate of energy emitted from an incandescent tungsten halogen light bulb as a function of wavelength (W/m2 per µm versus wavelength in µm). Assume the tungsten filament has a temperature of 3300 K. c. What fraction of the total energy emitted by the bulb produces light that we can see and what fraction is wasted as heat (λ > 800 nm)? d. Compare total area under your emissive power plot to theoretical area. Given the total power emitted...

A light-bulb manufacturer advertises that the average life for its light bulbs is 900 hours. A...

A light-bulb manufacturer advertises that the average life for its light bulbs is 900 hours. A random sample of 15 of its light bulbs resulted in the following lives in hours. 995 590 510 539 739 917 571 555 916 728 664 693 708 887 849 At the 10% significance level, test the claim that the sample is from a population with a mean life of 900 hours. Use the P-value method of testing hypotheses. Identify the null and alternative hypotheses,...

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