MATH PREP

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a quality control specialist for a restaurant chain takes a random sample of size 12 to check the amount of soda served in the 16 oz serving size. the sample mean is 13.30 with a sample standard deviation of 1.55 assume the underlying population is normally distributed. find the 95% confidence interval for the true population is normally distributed.

(12.32, 14.29)

suppose that an accounting firm does a study to determine the time needed to complete one persons tax forms. it randomly surveys 21 people . the sample mean is 23.6 hours and sample standard deviation of 7.0 hours the population distribution is assumed to be normal. construct a 90% confidence interval for the population mean time to complete the tax forms

(21.08, 26.11)

suppose average pizza delivery times are normally distributed with an unknown population mean and a population standard deviation of six minutes. a random sample of 28 pizza delivery is taken and has a sample mean delivery time of 36 minutes find a 95% confidence interval estimate for the population mean delivery time

(33.78, 38.22)

suppose scores on exams in statistics are normally distributed with an unknown population mean and a population standard deviation of three points. a random sample of 36 scores is taken and gives a sample mean (Sample mean score0 of 68. Find a 99% confidence interval for the true (population) mean of statistics exam scores.

(66.71, 69.29)

the mean height of 15-18 year old males from Chile from 2009 to 2010 was 170 cm with a standard deviation of of 6.28 cm. male heights are known to follow a normal distribution. let X= the height of a 15 to 18 year old male from Chile in 2009 to 2010. Then x-N(170, 6.28) Find the z-score of a 15 to 18 year old male from chile who is 168 cm?

-.32

in a lottery, there are 25 prizes of $50. Assuming that 1,000 tickets are to be issued and sold, what is the expected profit from this game if each ticket costs 5$?

-3.63

about 30% of students participate in a community volunteer program outside of school. 30 students are selected at random. find the probability that exactly 15 of them participate in a community volunteer program outside of school

.01

according to a recent article the average number of babies born with a significant hearing loss (deafness) is approximately 2 per 1,000 babies in a healthy baby nursery. The number climbs to an average of 30 per 1,000 babies in an intensive care nursery. suppose that 1,000 babies from healthy baby nurseries were randomly surveyed. find the probability that exactly 20 babies were born deaf

.0128

recently, a nurse commented that when a patient calls the medical advice line claiming to have the flu, the chance that he or she actually has the flu ( and not just a nasty cold) is only about 4%. Of the next 25 patients calling in claiming to have the flu, we are interested in how many actually have the flu. Find the probability that at least four of the 25 patients actually have the flu. (Note: "at least" = "greater than or equal to")

.01652

The population parameters below describe the full-time equivalent number of students (FTES) each year at Lake Tahoe Community College from 1976-1977 through 2004-2005 m= 1,000 (FTES) median= 1,014 (FTES) q= 474 (FTES) first quartile= 528.5 (FTES) third quartile= 1,447.5 (FTES) How many Standard deviations away from the mean is the median?

.03

a Nissan motor company ad reads "the average mans IQ is 107. the average brown trout's IQ is 4. so why can't man catch brown trout?" suppose that you believe that the brown trouts mean IQ is greater than 4 you can catch 12 brown trout a fish psychologist determines the IQs as follows: 5,4,7,3,6,4,5,3,6,3,8,5. x bar =4.92 s=1.62 whats the p value

.037

approximately 70% of statistics students do their homework in time for it to be collected and graded. each student does homework independently. in a statistics class of 50 students what is the probability that at least 40 will do their homework on time? (at least meaning greater than or equal to)

.08

the probability that san Jose wins any given game is .3694 based on a 13-year win history of 382 wins out of 1,034 games played ( as of a certain date) an upcoming monthly schedule contains 12 games.let X= the number of games won in that upcoming month. what is the probability that the san jose sharks win six games in that upcoming month

.1476

about 30% of students participate in a community volunteer program outside of school. 30 students are selected at random. find the probability that at least (greater than or equal to) 15 of them participate in a community volunteer program

.17

the total duration of baseball games in the major league in the 2011 season is uniformly distributed between 450 hours and 520 hours inclusive. What is the probability that the duration of games for a team for the 2011 season is between 480 and 500 hours?

.29

according to a gallop poll, 50% of american adults prefer saving over spending. Let X = the number of american adults out of a random sample of ten that prefer saving over spending. find the probability that more than 5 adults prefer saving.

.3770

what is the probability that the san jose sharks win at least five games (greater than or equal to five games) in that upcoming month

.4734

an unknown distribution has a mean of 45 and a standard deviation of 8. samples of size n=30 are drawn randomly from the population. what is the probability that the sample mean is between 45 and 50

suppose we toss a fair coin. let X= number of heads. find the standard deviation of X

the length of time it takes to find a parking space at 9 AM follows a normal distribution with a mean of 11 minutes and a standard deviation of 2 minutes find the probability that it takes at least 10 minutes to find a parking space.

.6915

.98

in a recent study reported oct 29th 2012 on the flurry blog the mean age of tablet users is 34. suppose the standard deviation is 15 years. take a sample of size n=100. find the probability that the sample mean age is more than 30 years (the reported mean age of tablet users in this particular study)

.99

if two events A and B are mutually exclusive then P(A and B)=

using this data identify the mode: 0, 25, 0, 50, 25

0 & 25

For the following data set calculate the standard deviation : 1,000,125; 1,000,127; 1,000,126

for the given data calculate the standard deviation: 10000; 10001; 10002

For the following data set calculate the mean : 1,000,125; 1,000,127; 1,000,126

1,000,126

a mens soccer team plays soccer zero, one, or two days a week. the probability that they play zero days is .2, the probability that they play one day is .05, and the probability that they play two days is .3. find the long term average or expected value, M, of the number of days per week the mens soccer team plays soccer.

1.1

find Z sub alpha/2 when alpha =.15

1.44

find t sub alpha/2 when alpha = .10 and n=15

1.76

60% of the time, it takes more than how many minutes to find a parking space?

10.49

the patient recovery time from a particular surgical procedure is normally distributed with a mean of 5 days and a standard deviation of 2 days what is the z score for a patient who takes 10 days to recover

2.5

the following data show the length of boats moored in a marina: 20; 25; 20; 15; 20; 20 find the mean.

the following data show the length of boats moored in a marina: 20; 25; 20; 15; 20; 20 find the median

using this data calculate the mean: 0, 25, 0, 50, 25

using this data identify the median: 0, 25, 0, 50, 25

The population parameters below describe the full-time equivalent number of students (FTES) each year at Lake Tahoe Community College from 1976-1977 through 2004-2005 m= 1,000 (FTES) median= 1,014 (FTES) q= 474 (FTES) first quartile= 528.5 (FTES) third quartile= 1,447.5 (FTES) What percent of the FTES were from 1,014 to 1,447.5?

25%

suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 50 feet. We randomly sample 49 fly balls. what is the 70th percentile of the distribution of the average of 49 fly balls

253.7

there are approximately one billion smartphone users in the world today. in the united states the ages 13-55+ of smartphone users approximately follow a normal distribution with approximate mean and standard deviation of 36.9 years and 13.9 years, respectively. find the 30th percentile

29.61

Listed are 9 ages find the 80th percentile: 21, 25, 26, 27, 29, 30, 31, 22, 18

if Q1 is 17 and Q3 is 50 what is the IQR?

For the following five salaries, calculate the IQR. The salaries are in dollars. 32,000; 54,000; 28;000; 54,000; 72,000

33,000

in a recent study the mean age of tablet users is 34 years suppose the standard deviation is 15 years. take a sample of size n=100 find the 75th percentile of the sample mean age

35.01

in a recent study reported oct 29th 2012 on the flurry blog the mean age of tablet users is 34. suppose the standard deviation is 15 years. take a sample of size n=100. find the 95th percentile for the sample mean age (to one decimal place)

36.5

the probability that san Jose wins any given game is .3694 based on a 13-year win history of 382 wins out of 1,034 games played ( as of a certain date) an upcoming monthly schedule contains 12 games. the expected number of wins for that upcoming month is

4.43

a citrus farmer who grows mandarin oranges finds that the diameters of mandarin oranges harvested on his farm follow a normal distribution with a mean diameter 5 cm and a standard deviation of .25 cm. find the 16th percentile

4.75

4.83

474

the total duration of baseball games in the major league in the 2011 season is uniformly distributed between 450 hours and 520 hours inclusive. What is the 60th percentile for the duration of games for a team for the 2011 season?

492

528.5 to 1,447.5

For the following five salaries, calculate the median. The salaries are in dollars. 32,000; 54,000; 28;000; 54,000; 72,000

54,000

in 2005 1,475,623 students heading to college took the SAT. The distribution of scores in the math section of the SAT follows a normal distribution with mean m= 520 and standard deviation q= 115 feet. What math SAT score is 1.5 standard deviations above the mean?

692.5

about 30% of students participate in a community volunteer program outside of school. 30 students are selected at random. find the mean

two thousand students took an exam. the scores on the exam have an appropriate normal distribution with a mean of m=81 points and a standard deviation q=15 points find the third quartile of one exam score.

91.12

919

Ho: m=4 Ha: m greater than 4

what's the null and alternative hypothesis... "at least 5% of adults ride the bus to work in Los Angeles

Ho: p less than or equal to .05 Ha: p greater than .05

let X= the length of time taken on the SAT. Suppose X is normally distributed with a mean of 2.5 hours and a standard deviation of .25 hours. a sample size of n=30 are drawn randomly from the population. what is the distribution of x bar

N(2.5, .032)

the length of time taken on the SAT for a group of students is normally distributed with a mean 2.5 hours and a standard deviation of .25 hours. A sample size of n=60 is drawn randomly from the population. what is the distribution of x bar.

N(2.5, .032)

suppose the length of songs in an album is uniformly distributed from 2 minutes to 4 minutes let X= the length of the songs in an album. hence, from the uniform, the mean, M is 3 and the standard deviation q is .58. if there are 100 songs, what is the distribution of the sample mean X bar

N(3, .058)

Jeffery as an eight- year old, established mean time of 16.43 seconds for swimming the 25 yard freestyle with a standard deviation of .8 seconds. his dad frank thought that Jeffery could swim the 25 yard freestyle faster using goggles. frank bought Jeffery a new pair of expensive goggles and timed Jeffery for 15 25 yard freestyle swims. for the 15 swims, Jeffery's mean time was 16 seconds frank thought that the goggles helped Jeffery to swim faster than 16.43 seconds which distribution is the most appropriate to use in order to find the p value for the hypothesis test

N(m, sq root of q/n)

a teacher believes that 85% of students in the class will want to go on a field trip to the local zoo she performs a hypothesis test to determine if the percentage is the same or different from 85% the teacher samples 50 students and 39 reply that they would want to go to the zoo which distribution is most appropriate to use in order to find the p value for the hypothesis test

N(p, sq root pq/n)

five students in your English class is a....

Sample

If a box plots box is on the left side of a graph and its tail extends longer to the right what is it?

Skewed Right

A fitness center has calculated the mean amount of time a client exercises in the center last week is 30 minutes. This is a....

Statistic

A marriage counselor is interested in the proportion of clients she counsels who stayed married. Whether clients stayed married or not is a....

Variable

You want to determine the average mean number of glasses of milk college students drink per day. Suppose yesterday, in your English class, you asked five students how many glasses of milk they drank the day before. The number of glasses of milk is....

Variable

state the type two error in a complete sentence for the following..."at most 60% of americans vote in presidential elections

We say that at most 60% of Americans vote in presidential elections but, in fact at least 60% vote

according to a recent survey of 1200 people, 61% feel that the president is doing an acceptable job. we are interested in the population proportion of people who feel the president is doing an acceptable job. what is the corresponding score for an 80% confidence interval

Z .10=1.28

The table shows the political party affiliation of each of 67 members of the US Senate in June 2012..... look at problem 1 on Exam 2

a No, Because p(D/U) not equal to P (D)

a lake tahoe community college instructor is interested in the mean number of days lake tahoe community college math students are absent during a quarter. what is the population shes interested in?

all lake tahoe community college math students

a study was done to determine the age number of times per week and the duration(amount of times) residents using a local park in texas. the first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed, the population is

all residents using a local park in San Antonio, TX

what is the probability given........ EX 20 on Exam 1 SG

b 13/37

The following data shows distance in miles from the homes of off campus students to the college. :0.5, 0.7, 1.1, 1.2, 1.3, 1.9, 2.0, 2.8, 3.5, 3.8, 4.4, 4.8, 4.9, 5.0, 5.2, 5.8, 5.9, 6.0, 7.1 which of the following is not appropriate for this data? stem plot histogram bar graph box plot

bar graph

according to a gallop poll, 50% of American adults prefer saving over spending. let X= the number of American adults out of a random sample of 10 who prefer saving over spending what is the most appropriate probability distribution of X

binomial

A study is done to determine the average tuition that San Jose state students pay per semester. Each student in the following samples is asked how much tuition he or she paid for the fall semester. what is the type of sampling in each case? A freshmen sophomore junior and senior years are numbered one two three and four respectively. A random number generator is used to pick two of those years. all students in those two years are in the sample.

cluster sample

a teacher wants to know if her students are doing homework, so she randomly selects rows two and five and then calls on all students in row two and all students in row five to present the solutions to homework problems to the class. the sampling method was...

cluster sampling

the table shows the political party affiliation of each of 67 members of the US senate 2012.....

the power of the test is 1- B we want this power to be close to 1 in order to increase the power of the test we need to

increase the sample size

know what 25% of the data is

its from one quartile to the next

a statistics instructor believes that fewer than 20% of evergreen valley students attended the opening midnight showing of harry potter movie. she surveys 84 of her students and finds that 11 of them attended the midnight showing the type 1 error is to conclude that the percent of EVC students who attended is...

less than 20% of evergreen valley college students when in fact it is greater than or equal to 20%

the length of time it takes to find a parking space at 9 AM follows a normal distribution with a mean of 11 minutes and a standard deviation of 2 minutes. based on the given information and numerically justified would you be surprised if it took 10 minutes to find a parking space?

what is the level of measurement? human eye colors

nominal

A camp director is interested in the mean number of letters each child sends during his or her camp session. The population standard deviation is known to be 2.5. a survey of 20 campers is taken. the mean is 7.9 and standard deviation is 2.8. What is the sampling distribution of the mean number of letters each child sends during his or her camp session?

normal distribution with the mean 7.9 and standard deviation 2.8/sq root 20

a sample of 16 small bags of the same brand of candies was selected. assume that the population distribution of bag weights is normal. the weight of each bag was then recorded. the mean weight was two ounces with a standard deviation of .12 ounces. the population standard deviation is known to be .1 ounce. which distribution is used in the confidence interval formula.

normal with a mean of 0 and a standard deviation of 1

the cost of unleaded gasoline in the bay area once followed an unknown distribution with a mean of 4.59 and a standard deviation of .10$ sixteen gas stations from the bay area are Randomly chosen. we Are interested in the average cost of gasoline for the 16 gas stations the distribution to use for the average cost of gasoline for the 16 gas stations is

normal with mean 4.59 and a standard deviation .10/square root 16

when a new drug is released it must be tested before approval from the FDA to market the drug. suppose the null hypothesis is " the drug is unsafe" what is the type 1 error

not to conclude the drug is safe when in fact it is safe

if two events are independent then P(A/B)=

p(A)

Ski Resorts are interested in the mean age that children take their first ski and snowboard lessons. They need this information to plan their ski classes optimally. The mean age of all children who take their first ski and snowboard lessons is a....

parameter

alpha is called the significance level what is the definition of alpha

probability of rejecting the null hypothesis when the null hypothesis is true

qualitative

zip code is what type of data

qualitative

duration (amount of time) is what kind of data?

quantitative continuous

number of times per month is what type of data?

quantitative discrete

a sample of 100 undergraduate students is taken by organizing the students names by classification. (freshmen, sophomore, junior, and senior) and then selecting 25 students from each

stratified sample

a study was done to determine average (number of times per week) and the duration(amount of times) residents using a local park in texas. the first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed, the sampling method was

systematic

a study was done to determine the age, number of times per week, and the duration of residents using a local park in san jose. the first house in the neighborhood around the park was selected randomly and then every eighth house in the neighborhood around the park was interviewed. the sampling method was....

systematic sample

the mean work for engineers in a start-up company is believed to be about 60 hours. a newly hired engineer hopes that it's shorter she asks ten engineering friends in start-ups for the lengths of their mean work weeks. based on the results that follow, should she count on the mean work week to be shorter than 60 hours? data (length of mean work week) : 70, 45, 55, 60, 65, 55, 55, 60, 50, 55. which distribution is most appropriate in order to find the p value for the hypothesis test?

t n-1

it is believed that lake Tahoe college algebra students get less than 7 hours of sleep per night on average. a survey of 22 ltcc algebra students generated a mean of 7.24 hours with a standard deviation of 1.93 hours at a level of significance of 5% do ltcc algebra students get less than 7 hours of sleep per night? the distribution used for this test is x bar

t21

it is believed that a stock price for a particular company will grow at a rate of 5$/ week. an investor believes the stock won't grow as quickly. the changes in stock price is recorded for ten weeks and are as follows:$ 4, 3, 2, 3, 1, 7,2,1,1, 2. x bar= 2.6 s=1.84 what is the conclusion?

there is sufficient evidence that the mean stock rate will not grow as fast as 5$ per week

68% of online courses taught at community colleges nationwide were taught by fulltime faculty. to test if 68% also represents California's percent for full time faculty teaching the online classes, long beach city college (LBCC) in California, was randomly selected for comparison. in the same year, 34 0f the 44 online courses LBCC offered were taught by full time faculty. what type of test is this?

two tailed

state the type 1 error in a complete sentence

we say that at least 5% of adults ride the bus to work in los angeles when, in fact at most 5% ride the bus.

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