1. At one high school, the mean time for running the 100-yd dash is 15.2 seconds with a standard deviation of 0.9 seconds. The times are very closely approximated by a normal curve. Find the percent of time that are: Between 14.3 and 16.1.
14.3-15.2/0.9=-0.9 =.-1.00= from z -score table is .341 or 34.1%
16.1-15.2/0.9=0.9=1.00 from z-score table is also .341 or 34.1%
add both together 34.1+34.1=68.2% round to 68%
2. Same question but: instead of 14.3 and 16.1 it request you from the percent that it will be greater than 16.1 seconds.
I am not sure where to start on this one.
3. A jar of peanut butter contains 445g with a standard deviation of 10.2 grams. Find the probability that a jar contains more than 453g. Assume normal distribution. Use the z-score to rounded to 2 decimal places.
453-445/10.2=8/10.2=0.7843 I know this is not right and need some assistance please.
14.3-15.2/0.9=-0.9 =.-1.00= from z -score table is .341 or 34.1%
16.1-15.2/0.9=0.9=1.00 from z-score table is also .341 or 34.1%
add both together 34.1+34.1=68.2% round to 68%
2. Same question but: instead of 14.3 and 16.1 it request you from the percent that it will be greater than 16.1 seconds.
I am not sure where to start on this one.
3. A jar of peanut butter contains 445g with a standard deviation of 10.2 grams. Find the probability that a jar contains more than 453g. Assume normal distribution. Use the z-score to rounded to 2 decimal places.
453-445/10.2=8/10.2=0.7843 I know this is not right and need some assistance please.