Download Hypothesis Test, Proportion

Hypothesis Test
Doctors at a hospital have designated a group of “at risk” patients for heart attacks. One
characteristic is high cholesterol, with an average cholesterol number of 280. A new treatment is
program is created. A random sample of 15 patients are given the treatment and their cholesterol is
measured. The results of the tests are: 233, 245, 199, 306, 229, 271, 208, 234, 256, 293, 315, 248,
287, 205, 291. Conduct a hypothesis test to determine if the treatment is effective (α = .01). What
assumption had to be made to conduct the test?
Hypothesis Test
A food company has developed a new recipe for their crust of their frozen pizza. A random sample
of 500 consumers are given the new frozen pizza to try. 363 say they think the new crust is an
improvement and they would be more likely to buy the frozen pizza in the future. The company
knows that approval rate has to be greater than 60% to justify changing the product. Conduct a
hypothesis test to determine if the company should change their product (α = .01).
Hypothesis test
A new corn hybrid is created. The old corn crop had a mean of 23 grams and standard deviation of
.2 grams. A sample of 10 ears of corn are weighed. Conduct a hypothesis test to determine if the
variation in weight has changed. Weight of sample: 24.36, 23.54, 24.18, 24.06, 23.74, 23.92,
24.06, 24.72, 24.56, 23.70.
In the following, state the null and alternative hypothesis (taken directly from text).
A new type of fertilizer is being tested on a plot of land in an orange grove to see if it
increases the amount of fruit production. The man number of pounds of fruit on this plot of
land with old fertilizer was 400 pounds.
A sample of 100 flounder (a fish) of a certain species have a sample mean weight of 21.5
grams Scientist want to perform a hypothesis test to determine how strong the evidence is
that the man weight differs from 20 grams.
A sample of 1004 adults will be conducted to see if they believe the federal government
should be limits on executive compensation. One highly paid executive claims that less than
50% of people believe that.
A marketing manager for a cell phone company claims that more than 35% of children aged
10-11 have cell phones. A survey of 5000 children will be conducted.
A new IQ test is created. The developer claims the population standard deviation is equal to
15. 25 people are tested.
2 
(n  1) s 2
 02
A company does a marketing study by selling a product at 10 different stores at 10 different prices.
Below presents their results.
Plot the above data below.
Find the Least Squares Regression Line: Qty = b0 + b1Price
Draw the Least Square Regression Line on the graph below
State r, R2, and calculate the Predicted Qty and the Residual
Interpret b1
Interpret the Y intercept
Find the X intercept and interpret that
If the price rises by $2, predict what happens to sales
If the company set a price of $10.75, what would be the predicted sales?
Price (X)
$7
9.50
8
11.5
10
10.5
11
9
7.5
8.5
Qty Sold (Y)
335
248
291
195
255
237
229
294
302
277
Pred Qty
Resid
Demand
360
340
320
Quantity Sold
Store
1
2
3
4
5
6
7
8
9
10
300
280
260
240
220
200
6
7
8
9
Price
10
11
12