Correct Answer: A. pelvic girdle, fore and hind limbs

Correct Answer: D. trypanosomiasis

Correct Answer: C. national chairman and general secretary

Correct Answer: B. water supply

Correct Answer: C. Mouse

Correct Answer: D. 20

Explanation

Recall how to find the mean: Mean/Average=Sum of all values/Number of values 30=(x)+(x+11)+(x?4)+(x?11)/4 4x?4=120 4x=124 x=31 Now, because the question asks you to find the smallest number, you need to find the value of x?11. x?11=31?11=20

Correct Answer: B. personification

Correct Answer: B) 3, 1, 14, 3, 2 and 7

Explanation

To determine the coefficients e, f, g, h, i, and j, we need to balance the given chemical equation:

\(eSn^{2+} + fCr_2O_7^{2-} + gH^+ \rightarrow hSn^{4+} + iCr^{3+} + jH_2O\).

First, let's balance the tin (Sn) atoms. Since tin is present in the form of Sn²⁺ on the left side and Sn⁴⁺ on the right side, to balance the tin atoms, we need 3 Sn²⁺ on the left and 3 Sn⁴⁺ on the right. So, e = 3 and h = 3:

Next, let's balance the chromium (Cr) atoms. Since Cr is present in the form of Cr₂O₇^2- on the left side and Cr³⁺ on the right side, to balance the chromium atoms, we need 1 Cr₂O₇^2- on the left and 2 Cr³⁺ on the right. So, f = 1 and i = 2:

Now, we need to balance the oxygen (O) atoms. There are 7 O atoms on the left side in the Cr₂O₇^2- ion. On the right side, O atoms are present only in the water (H₂O) molecules. So, to balance the O atoms, we need 7 H₂O molecules. Therefore, j = 7:

Finally, to balance the hydrogen (H) atoms and charge, we need 14 H⁺ ions on the left side. So, g = 14:

Thus, the balanced equation has the coefficients e = 3, f = 1, g = 14, h = 3, i = 2, and j = 7, which corresponds toOption B.

Correct Answer: D. vibratory

Correct Answer: D. 4.7

Explanation

Mean \(\bar{x} = \frac{\sum fx}{\sum f} = \frac{189}{40}\)

= \(4.725 \approxeq 4.7\)