college ststistics

posted by .

given x is a noramlly distributed random variable with a mean of 28 and a sd of 7 find p(x<28)

• college statistics -

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

However, since mean = 28, and in a normal distribution, the mean = median, and the median = 50th percentile, you would have your answer.

Similar Questions

1. Calculus

Suppose X is a random variable whose CDF is given by F(x) = 0, X<0 X^3, 0<X<1; 1, 1<X Then the mean for this random variable is: I don't understand how to do CDF (cumulitive distribution function) or how to get the mean …
2. Math

Random variables X and Y are both normally distributed with mean 100 and standard deviation 4. It is known that random variable X+Y is also a normal distribution. a. What is the mean of X+Y?
3. college ststistics

given x =237 u =2.00 and s=12.3 find z
4. stats

Opisthotrochopodus n sp. is a polychaete worm that inhabits deep sea hydrothermal vents along the Mid-Atlantic Ridge. According to an article by Van Dover et al. in Marine Ecology Progress Series (1999, vol 181 pp 201-214), the lengths …
5. Math

Suppose a baseball player had 211 hits in a season. In the given probability distribution, the random variable X represents the number of hits the player obtained in the game. x P(x) 0 0.1879 1 0.4106 2 0.2157 3 0.1174 4 0.0624 5 0.0060 …
6. Probability

Let N,X1,Y1,X2,Y2,… be independent random variables. The random variable N takes positive integer values and has mean a and variance r. The random variables Xi are independent and identically distributed with mean b and variance …
7. probability

Let N,X1,Y1,X2,Y2,… be independent random variables. The random variable N takes positive integer values and has mean a and variance r. The random variables Xi are independent and identically distributed with mean b and variance …
8. Statistics

X is a normally distributed random variable X with mean 15 and standard deviation 0.25. Find the values xL and xR of X that are symmetrically located with respect to the mean of X and satisfy P(xL < X < xR) = 0.80. (Hint. First …
9. Probability

Let N,X1,Y1,X2,Y2,… be independent random variables. The random variable N takes positive integer values and has mean a and variance r. The random variables Xi are independent and identically distributed with mean b and variance …
10. statistic

X is a normally distributed random variable X with mean 15 and standard deviation 0.25. Find the values xL and xR of X that are symmetrically located with respect to the mean of X and satisfy P(xL < X < xR) = 0.80. (Hint. First …

More Similar Questions