Question

first question asked:

Suppose every night I eat a snack. The amount of saturated fat (average fat) is 29 grams with a standard deviation of 4 grams. Find the probability that my saturated fat intake on any given day is below 32 grams. Answer = 0.773

second question:

If I have that same snack every night for the month straight- 31 days  - what is the probability that the average daily saturated fat intake is below 32 grams?

Answer 1

Solution :

Given that ,

mean = = 29

standard deviation = = 4

P(X< 32) = P[(X- ) / < (32-29) /4 ]

= P(z <0.75 )

Using z table

=0.7734

probability=0.773

(b)

n = 31

= 29

=  / n = 4/ 31=0.7184

P( < 32) = P[( - ) / < (32-29) /0.7184 ]

= P(z < 4.18)

Using z table  

= 1

probability=1