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UNIT 1, PART I AP® Statistics Practice Test 85

T7 The mean salary of all first-year workers at a com- Which of the following is a correct statement?
pany is $45,000. The mean salary of all workers who (A) Teens reported using the internet more frequently
have been at the company for more than one year is in 2014–2015 than in 2022.
$51,000. What must be true about the mean salary of (B) A majority of teens said “almost constantly” in
all workers at the company?
2022.
(A) It must be $48,000.
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(C) The percentage of teens who said “almost con-
(B) It must be larger than the median salary. stantly” doubled from 2014–2015 to 2022.
(C) It could be any number between $45,000 and (D) A majority of teens said “several times a day” in
$51,000. both 2014–2015 and 2022.
(D) It must be larger than $48,000. (E) The percentage of teens who said “about once a
(E) It cannot be larger than $50,000. day” doubled from 2014–2015 to 2022.
T8 The back-to-back stemplot shows the lifetimes of sev- T10 Researchers conducted an experiment to investi-
eral Brand X and Brand Y batteries. gate the effect of a new weed killer to prevent weed
growth in onion crops. They used two chemicals, the
Brand X Brand Y standard weed killer (S) and the new chemical (N),
1 and tested both at high and low concentrations on 50
1 7 test plots. They then recorded the number of weeds
2 2 Key: 4|2 represents
2 6 420–429 hours. that grew in each plot. Here are some boxplots of the
2110 3 results:
99775 3
3221 4 223334
4 56889 N—low conc.
4 5 0
5 5 S—low conc.

N—high conc.
One reason that someone might prefer a Brand Y
battery is S—high conc.
(A) a Brand Y battery had the longest lifetime. 0 10 20 30 40 50
(B) Brand Y batteries had the larger range of lifetimes. Number of weeds that grew
(C) Brand X batteries had a longer minimum lifetime.
Which of the following is not a correct statement
(D) Brand Y batteries had a longer median lifetime. about the results of this experiment?
(E) most Brand X batteries had a lifetime of at least (A) At both high and low concentrations, the new
300 hours. chemical results in better weed control than the
standard weed killer.
T9 How has teen internet use changed over time? The Pew
Research Center surveyed separate random samples of (B) For both chemicals, a smaller number of weeds
U.S. teens aged 13 to 17 in 2014–2015 and in 2022. The typically grew at higher concentrations than at
side-by-side bar graph summarizes the teens’ responses to lower concentrations.
the question, “About how often do you use the internet, (C) The results for the standard weed killer are less
either on a computer or a cellphone?” 100 variable than those for the new chemical.
60 (D) High and low concentrations of either chemical
have approximately the same effects on weed
50 2014–2015
growth.
2022
40 (E) Some of the results for the low concentration
Percent 30 of weed killer show a smaller number of weeds
growing than some of the results for the high
20 concentration.
10

0
Almost Several times About once Several times a
constantly a day a day week or less
Internet use frequency

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