The number of pedestrians crossing a street in downtown Providence during the morning rush hour is assumed to follow a normal distribution with mean 290 and standard deviation 50. a. What is the probability of more than 250 pedestrians crossing the street?

78.81% probability of more than 250 pedestrians crossing the street

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean and standard deviation , the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

a. What is the probability of more than 250 pedestrians crossing the street?

This is 1 subtracted by the pvalue of Z when X = 250. So

has a pvalue of 0.2119

1 - 0.2119 = 0.7881

78.81% probability of more than 250 pedestrians crossing the street

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)