To study how the design of controls and instruments can effect how easily people can use them, a study asked 25 right-handed people to turn a knob (with their right hands) which moved an indicator by screw action. Each person did this on two otherwise identical instruments; one with a right-hand thread (the knob turns clockwise) and one with a left-hand thread (the knob turns counterclockwise). The time required (in seconds) to move the indicator a fixed distance was recorded. The differences in times (recorded as left-hand thread time minus right-hand thread time) were calculated. These differences have a mean of 13.32 seconds and a standard deviation of 22.94 seconds. Researchers want to determine if all right-handed people can more easily use the instruments with a right-hand thread (that is, if the mean time is faster for right-handed people on instruments with a right-hand thread than on instruments with a left-hand thread). What is the value of the test statistic given the implied null and alternative hypotheses

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!

total amount to be paid = $19.5

step-by-step explanation:

given ,

original price = $25.99

discount = 25%

discount amount = 25% of original price

discount amount = 25/100   * 25.99

discount amount = $6.49

hence , the total amount to be paid = original price - discount amount

                                                            = $25.99 - $6.49

                                                            =$19.5

total amount to be paid = $19.5