Question

URGENT

Answer 1

Answer:

99.7%

Step-by-step explanation:

the standard deviation is 4 minuet but  there is always outliers so thats  why its not 100% of the time and the minutes are  coverd  by the deviation.  

Answer 2

Answer:

68%

Step-by-step explanation:

The attached normal table shows area under the standard normal curve that are to the left of a particular z-score.

To find the area between two z-scores, say $z_1 < z_2$, find the area to the left of $z_2$ then subtract the area to the left of $z_1$.  That difference is the area between the two z-scores.

38 minutes has a z-score $z_1=\frac{38-42}{4}=-1$

46 minutes has a z-score $z_2\frac{46-42}{4}=1$

Find z= 1.0 in the table. The area in that row is .8413.

Find z=-1.0 in the table.  The area in that row is .1587.

The difference, .8413 - .1587 = .6826 is the area under the normal curve between z=-1 and z=1.

.6826 is about 68%

Download pdf