Estadísticas preguntas y respuestas

ผลการวิเคราะห์ปริมาณตะกัวในเลือดโดยการทดลองซำ 5 ครั้ง ได้ค่าเฉลี่ย \( 11.8 \mathrm{mg} / \mathrm{L} \) และมีค่าเบี่ยงเบนมาตรฐานเป็น \( \pm 0.7 \) เมื่อนำตัวอย่างเลือด มาตรฐาน \( C R M \) ระบุปริมาณตะกั่วเท่ากับ \( 10.9 \mathrm{mg} / \mathrm{L} \) มาทำการวิเคราะห์ โดยวิธีเดียวกัน จงแสดงว่าผลการวิเคราะห์ (ค่าเฉลี่ย) แตกต่างอย่างมีนัยสำคัญจากค่าจริง หรือไม่ ที่ระดับความเชื่อมั่น \( 95 \% \)

A researcher wishes to compare the proportion of marijuana usage among students using usage categories low, medium, and high. She wants to determine if usage is related to parents' income, using categories low, medium, and high. She will analyze this data using the chi-square test. the two-sample procedures for proportions. the two-sample \( t \) test procedure. ANOVA.

5 Resultatet av en undersökning visas i två cirkeldiagram. Cirklarnas area är proportionell mot antalet elever. I undersökningen svarade 351 tjejer och killar ja. a) Hur många elever deltog i undersökningen? b) Hur många killar svarade nej?

The weights for newborn babies is approximately normally distributed with a mean of 5.1 pounds and a standard deviation of 1.1 pounds. Consider a group of 1300 newborn babies: 1. How many would you expect to weigh between 4 and 9 pounds? 2. How many would you expect to weigh less than 8 pounds? 3. How many would you expect to weigh more than 6 pounds? 4. How many would you expect to weigh between 5.1 and 10 pounds?

\begin{tabular}{l}\( \mid \) Which \( r \)-value implies the stronger linear relationship? Select one. \\ \( \square r=0 \) \\ \( \square r=-0.5 \) \\ \( \square r=-0.3 \) \\ \( \square r=-0.4 \) \\ \( \square r=-0.9 \) \\ \( \square r \) Question Help: \( \square \) Video \\ Submit Question \\ \hline\end{tabular}

(N) Gulliver tossed a coin 100 times and got 43 heads. What percent of the tosses were tails?

Ms Pitts has 220 students in her class. She would like to select a systematic sample of 20 students to answer a questionnaire. She numbers the students as they enter the lecture venue i.e. the \( 1^{\text {st }} \) student to enter gets assigned the number 1 , the \( 2^{\text {nd }} \) student to enter is assigned the number 2 etc. Ms Pitts randomly selects Student 10 to be the first student in her sample. Which student is the fourth to be selected for the sample? a) Student 11 b) Student 32 c) Student 43 d) Student 20 e) Student 30

Determine the minimum sample size required when you want to be \( 95 \% \) confident that the sample mean is within one unit of the population mean and \( \sigma=19.8 \). Assume the population is normally distributed. A \( 95 \% \) confidence level requires a sample size of (Round up to the nearest whole number as needed.)

In a survey of 2295 adults, 733 say they believe in UFOs. Construct a \( 99 \% \) confidence interval for the population proportion of adults who believe in UFOs. A \( 99 \% \) confidence interval for the population proportion is ( (Round to three decimal places as needed.) Interpret your results. Choose the correct answer below. B. With \( 99 \% \) confidence, it can be said that the population proportion of adults who believe in UFOs is between the endpoints of the given confidence interv C. The endpoints of the given confidence interval shows that \( 99 \% \) of adults believe in UFOs. D. With \( 99 \% \) probability, the population proportion of adults who do not believe in UFOs is between the endpoints of the given confidence interval.

In a survey of 3047 adults, 1459 say they have started paying bills online in the last year. Construct a \( 99 \% \) confidence interval for the population proportion. Interpret the results. A \( 99 \% \) confidence interval for the population proportion is (Round to three decimal places as needed.) Interpret your results. Choose the correct answer below. A. The endpoints of the given confidence interval show that adults pay bills online \( 99 \% \) of the time. B. With \( 99 \% \) confidence, it can be said that the sample proportion of adults who say they have started paying bills online in the last year is between the er the given confidence interval. C. With \( 99 \% \) confidence, it can be said that the population proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.