LET

1
LETS PLAYNAME THAT TEST..THEN, LETS

• DO THAT TEST!!
• Check condish
• Make Ho ha
• Null model
• Check yo stat wif model

2

• 1. Love that chicken! In 2004, 46 of seniors ate
  the chicken nuggets. You took a sample this year
  and found that 18/31 ate the nuggets. Do students
  now like nuggets more?

3

• 3. Fat Toads. Toads are known to eat flies. You
  are wondering if heavy toads eat more flies than
  lighter toads. You observe 5 heavy toads and 6
  lighter toads and find the following number of
  flies eaten per hour.
• Heavy 7, 8, 12, 33, 17
• Light 6, 2, 6, 7, 3, 4

4

• 5. Burritos. The average burrito at MOEs weight
  2.3 lbs. You are wondering if A new burrito place
  down the street offers burritos as large. You
  take the following sample of burrito weights.
• 2.1, 2.2, 1.4, 2.3, 2.1, 1.8, 1.4, 2.0
• Who has the larger burrito?

5

• 7. Texting. 48 of 50 sampled teachers admit to
  texting during the day. 60 of 30 students
  sampled regularly text during the day. Is there a
  significant difference?

6

• 15.AP SMARTS. Does AP stats make students
  smarter? IQ tests were given to students before
  and after they took AP Statistics. The following
  data was collected
• Before 142 122 135 136 158 115 98
• After 152 131 132 142 155 138 112
• Does AP Statistics make you smarter?

7

• 2. Hand Domination. Most people are definitely
  dominant on one side of their body either right
  or left. For some sports being able to use both
  sides is an advantage, such as batting in
  baseball or softball. In order to determine if
  there is a difference in strength between the
  dominant and non-dominant sides, a few
  switch-hitting members of some school baseball
  and softball teams were asked to hit from both
  sides of the plate during batting practice. The
  longest hit (in feet) from each side was recorded
  for each player. The data are shown in the table
  at the right. Does this sample indicate that
  there is a difference in the distance a ball is
  hit by batters who are switch-hitters?

8

• 4. Survey Responses Few people who receive
  questionnaires in the mail actually fill them out
  and return them often fewer than 10! One
  researcher thinks he can improve the response
  rate by including a coupon good for a free pint
  of ice cream along with the questionnaire. The
  researcher believes that people will want the ice
  cream, and feel guilty if they dont return the
  questionnaire. To test this conjecture he mails
  questionnaires with ice cream coupons to 150
  randomly selected people. After two weeks 41 of
  the surveys have been returned.

9

• 6. Scoring The table shows the average number of
  points scored in
• home and away games by 8 randomly selected NFL
  teams
• during the 2002 season. Assuming that the
  offensive
• performance of these teams is representative of
  other teams
• during this season and others, do these data
  provide evidence of
• a home field advantage when it comes to scoring?
• Ave. points scored
• Team Home Away
• Jets 24.3 21.2
• Ravens 19.8 19.8
• Texans 13.5 13.1
• 49ers 25.2 20.6
• Giants 18.9 23.0
• Bucs 26.5 20.8
• Eagles 24.1 25.5
• Packers 24.6 23.0

10

• 8. Pets A National Cancer Institute study
  published in 1991 examined the incidence of
  cancer in dogs. Of 827 dogs whose owners used the
  weed killer 2-4-D on their lawns or gardens, 473
  were found to have cancer. Only 19 of the 130
  dogs that had not been exposed to this herbicide
  had cancer. Is there a significant difference?

11

• 12. GIRLS BETTER THAN THE BOYS? Students at a
  local high school have GPAs that are normally
  distributed. It was thought that girls had higher
  GPAs than the boys. You take a random sample of
  35 boys and find that they have an average GPA of
  3.2 with a sample s.d. of .8. You also sample 41
  girls and find they have an average GPA of 3.6
  with a sample s.d. of 1.4. Do girls have higher
  GPAs?

12

• 9. Grapes An agronomist hopes that a new
  fertilizer she has developed will enable grape
  growers to increase the yield of each grapevine
  by more than 5 pounds. To test this fertilizer
  she applied it to 44 vines and used the
  traditional growing strategies on 47 other vines.
  The fertilized vines produced a mean of 58.4
  pounds of grapes with standard deviation 3.7
  pounds, while the unfertilized vines yielded an
  average of 52.1 pounds with standard deviation
  3.4 pounds of grapes. Do these experimental
  results confirm the agronomists expectations?

13

• 10. Car Insurance An insurance company advertises
  that 90 of their accident claims are settled
  within 30 days. A consumer group randomly selects
  104 of last years claims from the companys
  files, and finds that only 89 of them were
  settled within 30 days. Is the company guilty of
  false advertising?

14

• 11. Cigarettes Some of the cigarettes sold in the
  US claim to be low tar and have a mean tar
  level of 11.5 mg with a std dev of 1.2 mg. Are
  all the companies (generic and regular popular
  brands) close to that average? Samples of 15
  brands of each type were randomly chosen from the
  1206 varieties (no kidding) that are marketed.
  Their tar contents (mg/cig) are listed in the
  table below. Is there a significant difference in
  the published data?
• Type Milligrams of tar per cigarette
• Regular 18 10 14 15 15 12 17 11 14 17 12 14 15 15
  12
• Generic 9 5 10 4 8 9 9 3 7 12 6
  10 8 11 8

15

• 13. Brownies Wegmans (a food market chain) has
  developed a new store-brand brownie mix. Before
  they start selling the mix they want to compare
  how well people like their brownies to brownies
  made from a popular national brand mix. In order
  to see if there was any difference in consumer
  opinion, Wegmans asked 124 shoppers to
  participate in a taste test. Each was given a
  brownie to try. Subjects were not told which kind
  of brownie they got - that was determined
  randomly. 58 of the 62 shoppers who tasted a
  Wegmans brownie said they liked it well enough
  to buy the mix, compared to 66 of the others who
  said they would be willing to buy the national
  brand. Does this result indicate that consumer
  interest in the Wegmans mix is lower than for
  the national brand?

16

• 14. Taxes Waiters are expected to keep track of
  their income from tips and report it on their
  income tax forms. The Internal Revenue Service
  suspects that one waiter (well call him John)
  has been under-reporting his income, so they are
  auditing his tax return. An IRS agent goes
  through the restaurants files and obtains a
  random sample of 80 credit card receipts from
  people John served. The average tip size shown on
  these receipts was 9.68 with a standard
  deviation of 2.72.
• On his tax return John had claimed that his tips
  averaged 8.73. Based on this data, does the IRS
  have a case against him? Explain.

17

• 16. SENIORITIS. 35 of seniors earned less than
  an 80 in math Class in the second quarter. A
  sample of 65 seniors found that 33 scored under
  80 in their math class on the quarter 3 interim
  report. Is this evidence of senioritis?