Question

1. About % of the area under the curve of the standard normal distribution is outside the interval z=[−0.91,0.91]z=[-0.91,0.91] (or beyond 0.91 standard deviations of the mean).

2. Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P₁₁, the 11-percentile. Round to 3 decimal places. This is the temperature reading separating the bottom 11% from the top 89%.

P₁₁ = °C

3. Consider the discrete random variable XX given in the table below. Calculate the mean, variance, and standard deviation of XX.

XX	2	3	6	17	19	20
P(XX)	0.08	0.12	0.46	0.12	0.14	0.08

μμ =
σ2σ2 =
σσ =

What is the expected value of XX?

Please answer all the questions

Answer 1