Light bulbs are normally distributed with an average lifetime of 1000 hours and a standard deviation of 250 hours. The probability that a light bulb picked at random will last between 1400 and 1500 hours is about:

The probability that a light bulb picked at random will last between 1400 and 1500

P(14 00≤X≤1500) = 0.032

Step-by-step explanation:

Explanation:-

Given that mean of the Population = 1000

Given that the standard deviation of the Population = 250 hours

Let 'X' be the random variable in a normal distribution

Let  X = 1400

Let X = 1500

The probability that a light bulb picked at random will last between 1400 and 1500

P(x₁≤ X ≤x₂) = P(Z₁≤ Z ≤z₂)

                   = A( Z₂ ) -A(Z₁)

P(1400≤X≤1500)  = P(1.6≤ Z ≤2)

                            =  A(2 ) -A(1.6)

                           =  0.4772-0.4452

                          = 0.032

Final -

The probability that a light bulb picked at random will last between 1400 and 1500

P(14 00≤X≤1500) = 0.032

Of these value, the measured value  6.0 l is most precise and is accurate to the accepted measured value of 6 litres.

Step-by-step explanation:

The accepted value of the measurement = 6 litres

List of collected/measured values-

Of these value, the measured value  6.0 l is most precise and is accurate to the accepted measured value of 6 litres.

Except for this value, other values are quite small (like 1.1 l, 1.2 l, 1.5 l) than the acceptable measured value and hence can not be accepted.

The measured value of 8.1 l is more than the accepted value of 6.0 l