Warm-UpOn the driving range, Tiger Woods practices his golf swing with a particular club by hitting many, many balls. When Tiger hits his driver, the distance the ball travels follows a Normal distribution with mean 304 yards and standard deviation 8 yards. What percent of Tiger’s drives travel at least 290 yards?

What percent of Tiger’s drives travel between 305 and 325 yards?

Homework Questions

Calculator Stuff Go to pg 118 in your book and follow the steps for

the technology corner! ShadeNorm is the one we want!

2nd VARS – over to the Right – ShadeNorm(lowerbound, upperbound, )

Do the one from yesterday… Change window first (-4 to 4 on x and -.1 to .5 on

y) ShadeNorm(-1.25, 0.81, 0, 1) ENTER

It gives us the area under the curve!!

Examples Z < 1.39 (use -100 as your lower bound)

Z > -2.15 (use 100 as your upper bound)

-0.56 < z < 1.81

Find the proportion of observations that are greater than 1.53

Use Table A backwards Find the z-score for the 20th percentile

(Find the closest thing to 0.20 on your table)

Find the z-score where 45% of all observations are greater than z. (Remember…that means 55% below z)

Normalcdf(lower, upper, mean, std)

Look at Tiger’s drives again. What proportion of Tiger’s dries traveled at least 290 yards?2nd VARS – normalcdf(290, 400, 304, 8) = .95994 pretty close to our answer from the table!

What percent of Tiger’s drives travel between 305 and 325 yards?2nd VARS – normalcdf(305, 325, 304, 8) = ________ Little off – we rounded our z-scores from the

table to two decimal places…

Let’s practice…Cholesterol levels above 240 mg/dl may require medical attention. The distribution is Norman with a mean of 170 mg/dl and a standard deviation of 30 mg/dl. What percent of 14 year old boys have more than

240 mg/dl of cholesterol?

What percent have between 200 and 240 mg/dl?

What is the 1st quartile of the distribution?

Invnorm(%, 0, 1) This will tell you what the z-score is that

corresponds to a certain percentage (area) to the left under the curve.

What z-score has 40% below it?

What z-score has 80% above it?

Homework Pg 131 (41-54)