The monthly sales of a plywood shop are normally distributed with a standard deviation of ₹900. A statistical study of sales in the last nine months has found a confidence interval for the mean monthly sales with extremes ₹4663 and ₹5839. What were the average sales over the nine-month period?

If we reject the null hypothesis when it is true, we might be making

A company produces an item M whose mean sales per shop per month was found to be 84 dozens. After an advertisement, a sample of 26 shops was taken and mean sales was found to be 80 dozens with standard deviation of 9. Based on this data, which of the following is true?

(Given $t_{25}(0.05) = 2.06$)

[t = t-test statistic]

Arrange the following as per statistical inferences:

(A) Data Analysis

(B) Population

(C) Making Inferences

(D) Data Collection

Choose the correct answer from the options given below:

Match List-I with List-II

Choose the correct answer from the options given below:

Let two independent random samples of sizes $n_1$ and $n_2$ respectively have been drawn from the same normal population. Let $\overline{X_1}$ and $\overline{X_2}$ be the means and let $s_1$ and $s_2$ be their standard deviations. In order to test whether the the two sample means $\overline{X_1}$ and $\overline{X_2}$ differ significantly or not, the $t$-test statistic is given by

Consider the following hypothesis test:

$H_o: \mu \le 12$

$H_a: \mu > 12$

A sample of 25 provided a sample mean $\bar x=14$ and a sample standard deviation $s=4.32$. The degree of freedom is