Question

Let X denote the time in minutes (rounded to the nearest half minute) for a blood sample to be taken. The probability mass function for X is:

Answer 1

This question is incomplete, the complete question is;

Let X denote the time in minutes (rounded to the nearest half minute) for a blood sample to be taken. The probability mass function for X is:

x     0       0.5       1       1.5       2       2.5

f(x)  0.1     0.2     0.3    0.2     0.1       0.1

determine;

a) P( X < 2.5 )

B) P( 0.75 < X ≤ 1.5 )

Answer:

a) P( X < 2.5 ) = 0.9

b) P( 0.75 < X ≤ 1.5 ) = 0.5

Step-by-step explanation:

Given the data in the question;

The probability mass function for X is:

x     0       0.5       1       1.5       2       2.5

f(x)  0.1     0.2     0.3    0.2     0.1       0.1

a) P( X < 2.5 )

P( X < 2.5 ) = p[ x = 0 ] + p[ x = 0.5 ] + p[ x = 1 ] + p[ x = 1.5 ] + p[ x = 2 ]

so

P( X < 2.5 ) = 0.1 + 0.2 + 0.3 + 0.2 + 0.1

P( X < 2.5 ) = 0.9

b) P( 0.75 < X ≤ 1.5 )

P( 0.75 < X ≤ 1.5 ) = p[ x = 1 ] + p[ x = 1.5 ]

so

P( 0.75 < X ≤ 1.5 ) = 0.3 + 0.2

P( 0.75 < X ≤ 1.5 ) = 0.5