Statistics Midterm

The student body of a large university consists of 65% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 6 are male?

0.0253

x is a normally distributed random variable with a mean of 7 and a standard deviation of 2. The probability that x is between 6.48 and 7.56 is

0.2128

For a standard normal distribution, the probability of obtaining a z value between -1.4 to - 0.35 is

0.2824

The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 6 are female?

0.3154

A group of students had dinner at a local restaurant. The total bill for the dinner was $364.99. Each student paid his/her equal share of the bill, which was $21.47. How many student's were at the dinner?

17

The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0-9 20 10-19 80 20-29 200 30-39 100 The midpoint of the third class is

24.5

The closing stock price of MNM Corporation for the last 7 trading days is shown below. Day Stock Price 1 24 2 27 3 24 4 28 5 25 6 30 7 31 The variance is

8

Twenty percent of the students in a class of 400 are planning to go to graduate school. The standard deviation of this binomial distribution is

8

Consider the probability distribution below. x f(x) 10 .2 20 .4 30 .3 40 .1 The variance of x equals

81

Which of the following is not a measure of variability?

The midrange

A histogram is

a graphical presentation of a frequency or relative frequency distribution.

Each individual outcome of an experiment is called

a sample point.

The sum of deviations of the individual data elements from their mean is

always equal to zero.

The standard deviation of a normal distribution

cannot be negative.

Data that provide labels or names for categories of like items are known as _____ data.

categorical

The process of capturing, storing, and maintaining data is known as

data warehousing

The mean of a standard normal probability distribution

is always equal to zero.

The center of a normal curve

is the mean of the distribution.

The measure of location which is the most likely to be influenced by extreme values in the dataset is the

mean

Which of the following provides a measure of central tendency for the data?

mean

The most frequently occurring value of a data set is called the

mode

The percent frequency of a class is computed by

multiplying the relative frequency by 100.

Which of the following symbols represents the size of the sample?

n

The variance Var(x) for the binomial distribution is given by equation

np(1-p)

A restaurant asks their customers to fill out a questionnaire indicating whether their service was excellent, very good, good, or poor. The rating scale used is an example of the _____ scale.

ordinal

A numerical description of the outcome of an experiment is called a

random variable.

The difference between the largest and the smallest data values is the

range

Height is an example of a variable that uses the _____ scale.

ratio

If two events are independent, then

the product of their probabilities gives their intersection.

Data is

the raw material of statistics.