📊 statistics

1. **بيان المشكلة:** لدينا بيانات مبيعات المنتج (X) وحجم الطلب على المنتج (Y) ونريد:

1. The problem asks how to describe the correlation between two points on a graph. 2. Correlation measures the strength and direction of a linear relationship between two variables

1. The problem asks us to estimate the number of CDs sold in 2006 based on the trend from 1999 to 2005 shown in the scatter plot. 2. From the description, the number of CDs sold de

1. **Problem statement:** We have a sample of 12 hypertensive smoking men aged 35-70 with sample mean serum cholesterol level $\bar{x} = 217$ mg/100 ml and population standard devi

1. The problem is to match each histogram with its corresponding normal Q-Q plot given standardized data. 2. Histograms show frequency distributions; normal Q-Q plots assess how cl

1. Let's start by stating the problem: We want to understand how to find the z-score when given a value of 0.74. 2. The z-score formula is: $$z = \frac{X - \mu}{\sigma}$$ where:

1. The problem states that the significance level is $\alpha = 0.05$ and the P-value from the hypothesis test is $0.2934$. 2. For hypothesis testing, we compare the P-value with $\

1. **Problem Statement:** We want to find the sample size $n$ needed to estimate the percentage of adults gambling online with a 95% confidence level and a margin of error of 4 per

1. **State the problem**: We need to find the two z-scores symmetric about 0 that mark the middle shaded region in a standard normal distribution, where the shaded area is 0.48. 2.

1. **State the problem:** We have a poll of 511 human resource professionals where 45.8% said body piercings and tattoos are big personal grooming red flags. We need to answer part

1. **Problem Restatement:** We have overhead reach distances for adult females that are normally distributed with a mean $\mu = 200$ cm and standard deviation $\sigma = 8$ cm. We w

1. We are given a normal distribution for IQ scores with mean $\mu = 100$ and standard deviation $\sigma = 15$. 2. The problem states that the area to the right of the score $x$ is

1. The problem requires finding the standard deviation of a sample using the given values: sample size $n=302$, upper bound $U=13.8$, and lower bound $L=5.3$. 2. To proceed, we fir

1. The problem gives n = 302 (sample size), U = -13.8 (upper bound), and L = -5.3 (lower bound). 2. Assuming these bounds represent a confidence interval, the range is $$U - L = -1

1. **State the problem:** We are given the formula for the standard error or margin of error as $\sigma= \frac{2}{U-L} \times z_n$, where $U$ and $L$ are known values. 2. **Underst

1. The problem is to find the standard deviation $\sigma$ from given confidence intervals.\n2. Confidence intervals are typically given as $\bar{x} \pm z \frac{\sigma}{\sqrt{n}}$,

1. **State the problem:** We have a sample of 30 emergency room patients with an average waiting time of $174.3$ minutes and a population standard deviation of $46.5$ minutes. We w

1. **State the problem:** We want to estimate the population mean number of days it takes to sell a Chevrolet Aveo based on the sample data. We have a sample mean $\bar{x} = 54$ da

1. The problem is to find the t-value for a sample mean compared to the national average. Given: sample size $n=16$, sample mean $\bar{x}=74$, sample standard deviation $s=8$, popu

1. **Problem Statement:** Determine which of the given statements about the t statistic and standard errors are FALSE. 2. **Evaluate Each Statement:**

1. The researcher conducted a t-test resulting in $t(14) = 2.25$ with a $p$-value less than $0.05$. 2. The significance level (alpha) is $\alpha = 0.05$.