normal distribution

If the distribution of IQ scores is bell-shaped, with a mean of 100 and a standard deviation of 15, then approximately ____% of IQ scores are less than 55? A bell-shaped curved implies a normal distribution. By using our empirical rule calculator, we see that: 99.7% of all normal distribution...

A fuel injection system is designed to last 18 years, with a standard deviation of 1.4 years. What is the probability that a fuel injection system will last less than 15 years? Using our z-score calculator, we see that: P(X < 15) = 0.416834

For the normal distribution with parameters μ = 4, σ = 3 ; calculate P(x > 1) Using our calculator, we get P(x > 1) = 0.841345

μ = 5, σ = 4 ; calculate P(0 < x < 8) This is the same as P(x < 8) - P(x < 0). P(x < 8) using our calculator is 0.773373 P(x < 0) using our calculator is 0.10565 So we have 0.773373 - 0.10565 = 0.667723

Compared to the normal distribution, the t distribution has ___ values at the top and ___ at the tails. a. More; less b. More; more c. Less; less d. Less; more d. Less; more t value chart is wider and flatter

A compact disc is designed to last an average of 4 years with a standard deviation of 0.8 years. What is the probability that a CD will last less than 3 years? Using our Z-score and Normal distribution calculator, we get: 0.10565

The distribution of actual weights of 8 oz chocolate bars produced by a certain machine is normal with µ=8.1 ounces and σ=0.1 ounces. A sample of 5 of these chocolate bars is selected. What is the probability that their average weight is less than 8 ounces? Calculate Z score and probability...