What is the standard error of the difference between two sample proportions, $(P_x-P_y)$

The label on a jar of jam carries the words 'minimum contents $272 \mathrm{g}$'.

Explain why, in practice, the average contents need to be greater than $272 \mathrm{g}$.

What is the standard error of the difference between two sample proportions, $(P_x-P_y)$

Find standard error of the sample proportion $P=0.45$ when the population proportion is $0.5$ and the given sample size is $100$

The label on a jar of jam carries the words 'minimum contents $272 \mathrm{g}$'.

The mass of jam dispensed by a machine used to fill the jars is a normally distributed random variable with mean $276 \mathrm{g}$. The variance of the mass of the jam, in ${\mathrm{grams}}^2$, dispensed by the machine is $1.8^2$. Each week there is a check to see if the mean mass dispensed by the machine is $276 \mathrm{g}$. One particular week a sample of eight jars is checked. The mean mass of jam in these jars is $277.7 \mathrm{g}$. Carry out an appropriate hypothesis test at the $5\%$ level of significance, stating any assumptions you have made.

describe in detail : standard error of a statistic

Calculate standard error of the sample means, when sample mean is $100$, sample size is $64$ and population standard deviation is $24$.

The given length of time a charged smartphone battery will last is normally distributed with mean $24$ hours. The variance of the time taken, in minutes, for the smartphone to work is $1$. The variance of the length of time time taken, in hours squared, for the battery to last is $1$. Sami tests a random sample of five batteries;

the sample mean time is $23.2$ hours. Investigate at the $5\%$ level of significance whether the time batteries last is less than the time given, stating any assumption(s) you make.

Calculate standard error of the sample means, when sample mean is $100$, sample size is $25$ and population standard deviation is $50$.

What is the standard error of the sample proportion under $H_0$?

Calculate standard error of the sample mean, when sample mean is $100$, sample size is $64$ and population standard deviation is $24$

The manufacturer of a certain smartphone advertises that the average charging time for the battery is $80$ minutes with standard deviation $2.6$ minutes. Owners of these smartphones suggest that the time is longer. A random sample of the phones were charged from $0$ to $100\%$ and their times, in minutes, are as follows.

$\begin{array}{llllllll}88& 85& 82& 77& 86& 75& 80& 79\end{array}$

Investigate at the $5\%$ level of significance whether or not the manufacturer's claim is justified, stating any assumption(s) you have made.

Define standard error of a statistic

What is the standard error of the difference between two sample proportions, $(P_x-P_y)$

If $m=35,n=40,x=10.8,y=11.9$, $S_X=3$ and $S_Y=4$, then calculate standard error of $\stackrel{-}{X}-\stackrel{-}{Y}$

The standard error of the sample proportion under $H_0$?