|
INSTRUCTIONSUnless otherwise stated in the question all answers should: - be written WITHOUT spaces e.g. P=2l+2w- sets should be written with the SMALLEST number first e.g. {-3,-1,5,7}- be written with NUMBERS FIRST, followed by letters in ALPHABETICAL ordere.g. -2bcm, -3x2 - use ^ for powers e.g. xΛ2 squared is x2- be written in descending powers e.g. -3x3+x2-3x+1- use <= for less than or equals; >= for greater than or equals- use sqrt for square root- use cubert for cube root A group of students has measured the heights of 90 trees. The class calculate the mean height to be 12.4 m with standard deviation, 5.35 m. One student notices that two of the measurements, 44.5 m and 43.2 m, are much too big and must be wrong. (a) How many standard deviations away from the mean of 12.4 is the value 44.5? The incorrect measurements of 44.5 m and 43.2 m must be removed from the data. (b) Calculate the new value of the mean after removing the two unwanted values. m The following is part of a display on the notice board of a bank in the United Kingdom, many years ago. It shows the exchange rate between one British pound (GBP) and other currencies. This question continues on the next slide. Geraldine eats a meal in a restaurant while on holiday in Greece. The meal costs 4256 drachma (DR). (a) Use the bank-selling price to calculate the cost of the meal in British pounds. The Williams family go to Germany. Before leaving, they change 600 GBP into German marks. (b) Calculate the number of German marks they receive for 600 GBP , giving your answer correct to two decimal places. They spend 824 DM in Germany, and on returning to the United Kingdom, they change their remaining German marks into British pounds. (c) Calculate the number of British pounds they receive, correct to two decimal places. GBP GBP DM A basketball is dropped vertically. It reaches a height of 2 m on the first bounce. The height of each subsequent bounce is 90% of the previous bounce. (a) What height does it reach on the 8th bounce? (b) What is the total vertical distance travelled by the ball between the first and sixth time the ball hits the ground. m m The table below shows the percentage, to the nearest whole number, scored by candidates in an examination. The table at the right is the cumulative frequency table for the marks. Calculate the values of s and of t. t = s = |