DP Mathematics: Applications and Interpretation Questionbank

Assuming that the shopkeeper’s claim is correct, find the probability that the weight of six randomly chosen carrots is more than two times the weight of one randomly chosen broccoli.

Find the least value of $n$ required to ensure that the width of the confidence interval is less than $2 \text{grams}$.

Find the significance level for this test.

Given that the weights of the broccoli actually follow a normal distribution with mean $392 \text{grams}$ and variance $80 {\text{grams}}^2$, find the probability of Anjali making a Type II error.

Use the given value of $s_n$ to find the value of $s_{n-1}$.

Hence show that the variance of the proportion of marked fish in the sample, $\text{Var}\left(\frac{X}{300}\right)$, is $0.000425$.

Taking the value for the variance given in (d) (ii) as a good approximation for the true variance, find the upper and lower bounds for the proportion of marked fish in the lake.

Hence find upper and lower bounds for the number of fish in the lake when $t=8$.

have a total mass greater than $6.0 \text{kg}$.

Given this result, comment on the validity of the linear model used in part (a).

both have a mass greater than $3.0 \text{kg}$.

Show that an estimate for $\text{Var}\left(X\right)$ is $38.25$.

Find the probability that a bag selected at random weighs more than $1 \text{kg}$.

Find the standard deviation of the weights of these bags of apples.

Find the mean weight of a bag of apples.

Suggest, with justification, a valid conclusion that Talha could make.

Find an unbiased estimate for the mean number $\left(\mu \right)$ of chocolates per packet.

Use the formula $s_{n-1}^2=\frac{\text{Σ}{x}^2-{\displaystyle \frac{{\left(\text{Σ}x\right)}^2}{n}}}{n-1}$ to determine an unbiased estimate for the variance of the number of chocolates per packet.

Find a $95\%$ confidence interval for $\mu$. You may assume that all conditions for a confidence interval have been met.

A statistician in the company suggests it would be fairer if the company passes the inspection when the mean weight of five randomly chosen bags is greater than $950 \text{g}$.

Find the probability of passing the inspection if the statistician’s suggestion is followed.

Find an unbiased estimate of the population mean of $d$.

Find an unbiased estimate of the population variance of $d$.

their mean standardized score.

the standard deviation of their standardized score.

Find $s_{n-1}$ for this sample.

Find a 95 % confidence interval for the population mean, giving your answer to 4 significant figures.

The bags are labelled as being 1.5 kg mass. Comment on this claim with reference to your answer in part (b).

Perform a suitable test, at the 5% significance level, to determine if it is easier to achieve a distinction on the new exam. You should clearly state your hypotheses, the critical region and your conclusion.

Use the normal distribution model to find the score required to pass.

Find unbiased estimates for the population mean.

Find the probability of making a Type I error.

Given that $p=0.2$ find the probability of making a Type II error.

Find unbiased estimates for the population Variance.

Show that the expected frequency for 20 < $x$ ≤ 4 is 31.5 correct to 1 decimal place.

Perform a suitable test, at the 5% significance level, to determine if there is a difference between the mean scores of males and females. You should clearly state your hypotheses, the p-value and your conclusion.

Perform a suitable test, at the 5% significance level, to determine if the scores follow a normal distribution, with the mean and variance found in part (a). You should clearly state your hypotheses, the degrees of freedom, the p-value and your conclusion.

Calculate unbiased estimates of the population mean and the population variance.

State suitable hypotheses.

Calculate the value of the ${\chi }^2$ statistic and state your conclusion using a 10% level of significance.

Find the probability that a randomly chosen male bird weighs between 4.75 kg and 4.85 kg.

Find the probability that the weight of a randomly chosen male bird is more than twice the weight of a randomly chosen female bird.

Two randomly chosen male birds and three randomly chosen female birds are placed on a weighing machine that has a weight limit of 18 kg. Find the probability that the total weight of these five birds is greater than the weight limit.

Find the probability that the time taken for a randomly chosen customer to be dealt with by an employee is greater than 180 seconds.

Find the probability that the time taken by an employee to deal with a queue of three customers is less than nine minutes.

At the start of the day, one employee, Amanda, has a queue of four customers. A second employee, Brian, has a queue of three customers. You may assume they work independently.

Find the probability that Amanda’s queue will be dealt with before Brian’s queue.

$\text{E}\left(2X+7Y\right)$.

Var$\left(4X-3Y\right)$.

$\text{E}\left(X^2-Y^2\right)$.

Find the probability that a fish from this lake will have a weight of more than 560 grams.

The maximum weight a hand net can hold is 6 kg. Find the probability that a catch of 11 fish can be carried in the hand net.

State the distribution of your test statistic, including the parameter.

Find the p-value for the test.

State the conclusion of the test, justifying your answer.

State suitable hypotheses for the test.

Find the product-moment correlation coefficient $r$.

State the p-value and interpret it in this context.

Use an appropriate regression line to estimate the weight of a fish with length 360 mm.

State the distribution of $\overline{X}$ giving its mean and variance.

Find an unbiased estimate for $\mu$.

Find an unbiased estimate for ${\sigma }^2$.

Find a 90 % confidence interval for $\mu$.

Find the $p$-value for the test.

Write down the conclusion reached.