Statıstıcs I

Yanıt Açıklaması: There are 3 female students who got 70 and 3 who got 75, which is the highest number of females around these grades.

Yanıt Açıklaması: Midrange = (x_min + x_max) / 2 = (14 + 96) / 2 = 55

Yanıt Açıklaması: Histograms will help us to identify the centre, shape and symmetry of the data. A histogram can tell us about the peaks and extreme values..

Yanıt Açıklaması: A properly created graph can report various information of the data in a visual form. For instance, the shape of the distribution of the data, the relation between two sets of data, the most repeating observations, outliers, peaks, summary statistics (minimum, maximum, range, mean, median) etc. can be identified from graphics. The correct answer is E.

Yanıt Açıklaması: Several characteristics define a data set’s structure and properties. Element, Variable, Case and Observation are the key components of data sets.

Yanıt Açıklaması: Line chart is often used to display the trends in a continuous data over a period of time. Line chart also works well with discrete (ordered) or categorical types of data. The chart is constructed by intersecting the points by lines on the x-axis. Some line charts are used to draw in two or three dimensions. Additionally, some of the line charts are very helpful to show the relationships for multivariate data.The correct answer is E.

Yanıt Açıklaması: In order to be able to prove that aspirin is the cause of the improvement in health, an experiment needs to be conducted where conditions are controlled between those taking aspirin and those not taking it. Such an experiment might be designed as follows, restricted to men, for example, since the effects are suspected to be different for men and women.

Yanıt Açıklaması: The total time for the activities is 24 hours. 360 degrees represent 24 hours. So, one hour represented with 360/24 degree=15 degree. The angle of studying equals to 15x4=60 degrees.

Yanıt Açıklaması: Observation i­s making direct examination and taking measurements of an ongoing activity. In other words, observation i­s way of obtaining data by watching behavior, events, or noting physical characteristics in their natural setting. One of the most common methods of collecting data from individuals ­is ­interviewing. In an ­interview procedure, a researcher or observer asks the questions from a questionnaire and records the ­individual’s answers. In a self-enumerati­on method, ­individuals answer the questions printed on a questionnaire paper, or displayed on a computer monitor. In other words, self-enumerat­ion method refers to the completion of survey questionnaires by the respondents themselves.

Yanıt Açıklaması: The Winsorized mean can be calculated with the remaining values after replacing a certain number or the proportion of the values at the low and high end of the sorted data. First the data set is ordered from smallest to largest 3,3,4,5,6,6,7 then we will find how many data points will be replaced, k, since the winsorizing is 30% and there are 7 observations, the value of k is k = np = 7×0.30 = 2,1 which is nearly 2. Therefore, 2 observation from each end of the sorted data will be replaced with those next in magnitude, these observations are as follows, 3 is replaced with 4 and 7 and 6 is replaced with 6. The set yields to 4,4,4,5,6,6,6. The 30% Winsorized mean of the data set is (4+4+4+5+6+6+6)/7= 5. The answer is D.

Yanıt Açıklaması: Line chart is often used to display the trends in a continuous data over a period of time.

Yanıt Açıklaması: Since almost half of the population is female, he is making a mistake in sampling. The parfume preferences of males and females could be different and his sample is male biased.

Yanıt Açıklaması: Sometimes raw data in a frequency distribution table yield more useful information. To construct a frequency distribution table, the measurement categories and the number of responses within a given measurement category are used.

Yanıt Açıklaması: Data such as gender, hometown and branch do not represent a computational score. They can only be used to categorize the sample.

Yanıt Açıklaması: Histogram is a graph that is very similar to a bar chart except that bar charts are drawn for qualitative data but histograms are drawn for continuous data. The correct answer is C.

Yanıt Açıklaması: The researcher is making an observation.

Yanıt Açıklaması: Dot plot is almost the easiest of the graphs. It can be drawn by hand easily while collecting data. Dot plot will be very useful when the number of objects in our study is rather small such as up to 50 observations. Dot plot is generally used to investigate univariate (quantitative) data, but sometimes it is used to compare two variables.

Yanıt Açıklaması: Only the statement in E is true. For left-skewed distributions meanmedian>mode. But for normal distributions all these measures are same.

Yanıt Açıklaması: mean = total / n mean = 73 / 10 mean = 7.3

Yanıt Açıklaması: (8 x 27 x 64) -3 = 2 x 3 x 4 = 24